Bump version to 0.21.0; rework changelog, contributors, and docs

Release:
- Bump version to 0.21.0 and regenerate tusb_option.h, library.json,
  repository.yml, sonar-project.properties, boards.rst, dependencies.rst
- Add 0.21.0 release notes and split the changelog into per-release files
  under docs/info/changelog/ (date out of title, driver/class groups as
  sub-headings, DCD & HCD section after Device/Host stacks)

Contributors:
- Credit each release's PR authors in a Contributors section
- Drop the curated contributors page; add MAINTAINERS.rst

Docs:
- Update Code of Conduct to Contributor Covenant 3.0 (keep it in the repo,
  remove it from the built docs)
- Sidebar: add a home entry, rename the group to "Documentation", move
  Changelog into it, add a GitHub Sponsor button, merge external links,
  rename FAQ; hide the inline toctree on the landing page
- Add the make-release skill and update the AGENTS.md release process

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

1 files changed, 0 insertions, 215 deletions

diff --git a/CONTRIBUTORS.rst b/CONTRIBUTORS.rst
deleted file mode 100644
index 451ac0783..000000000
--- a/CONTRIBUTORS.rst
+++ /dev/null
@@ -1,215 +0,0 @@
-************
-Contributors
-************
-
-Special thanks to all the people who spent their precious time and effort to help this project so far.
-list contributors and their awesome work for the stack:
-
-Notable contributors
-====================
-
-(sorted alphabetically)
-
-`Adafruit Team <https://github.com/adafruit>`__
------------------------------------------------
-
--  Main supporter and sponsor for hardware boards and kits
--  Discussion and suggestion for feature and improvement
--  Design the project logo
-
-
-`Gordon McNab <https://github.com/ftdigdm>`__
----------------------------------------------
-
--  Add new DCD port for Bridgetek FT90x and FT93x
-
-
-`Ha Thach <https://github.com/hathach>`__
------------------------------------------
-
--  *Author and maintainer*
--  Most features development
-
-
-`Heiko Kuester <https://github.com/IngHK>`__
---------------------------------------------
-
--  Add CH34x and PL2303 support (CDC host)
--  Improve FTDI and CP210x support (CDC host)
-
-
-`Hristo Gochkov <https://github.com/me-no-dev>`__
--------------------------------------------------
-
--  Improve ESP32s2 DCD
-
-
-`Jacob Berg Potter <https://github.com/j4cbo>`__
-------------------------------------------------
-
--  Add new class driver for network CDC-NCM
-
-
-`Jan Dümpelmann <https://github.com/duempel>`__
------------------------------------------------
-
--  Improve transfer performance for Synopsys DCD for STM32 MCUs
-
-
-`Jeff Epler <https://github.com/jepler>`__
-------------------------------------------
-
--  Improve MIDI class driver
-
-
-`Jerzy Kasenberg <https://github.com/kasjer>`__
------------------------------------------------
-
--  Add new DCD port for Dialog DA1469x
--  Add new DCD port for PIC32MZ
--  Add new class driver for Bluetooth HCI
--  Add ISO transfer for STM32 Synopsys, Nordic nRF, Dialog DA1469x
--  Improve Audio driver and add uac2\_headset example
--  Improve STM32 Synopsys DCD with various PRs
-
-
-`J McCarthy <https://github.com/xmos-jmccarthy>`__
---------------------------------------------------
-
--  Add new DFU 1.1 class driver
--  Add new example for dfu
-
-
-`Kamil Tomaszewski <https://github.com/kamtom480>`__
-----------------------------------------------------
-
--  Add new DCD port for Sony CXD56 (spresnese board)
-
-
-`Kay Sievers <https://github.com/kaysievers>`__
------------------------------------------------
-
--  Improve MIDI driver with packet API
-
-
-`Koji KITAYAMA <https://github.com/kkitayam>`__
------------------------------------------------
-
--  Add new DCD and HCD port for NXP Kinetis KL25
--  Add new DCD and HCD port for Renesas RX family (RX600, RX700 ..) with GR-CITRUS, RX65n target board
--  Add new DCD and HCD port for Mentor musb with MSP432E4
--  Add new class driver for USB Video Class (UVC 1.5)
-
-`Nathan Conrad <https://github.com/pigrew>`__
----------------------------------------------
-
--  Add new DCD port for STM32 fsdev Fullspeed device for STM32 L0,
-   F0, F1, F3 etc ...
--  Add new class driver for USB Test and Measurement Class (USBTMC)
--  Various improvement e.g Zero-length packet, Lint setup
--  Board support for STM32F070RB Nucleo, STM32F303 Discovery
-
-
-`Peter Lawrence <https://github.com/majbthrd>`__
-------------------------------------------------
-
--  Add new DCD port for Nuvoton NUC 120, 121, 125, 126, 505
--  Add new class driver for network RNDIS, CDC-ECM
--  Enhance CDC-NCM network driver to compatible with RNDIS/ECM
--  Add *net\_lwip\_webserver* example for demonstration of usbnet with lwip
--  Board support for NuTiny NUC120, NUC121s, NUC125s, NUC126V, NUC505
--  Improve multiple cdc interfaces API & add cdc\_dual\_ports example
-
-
-`Rafael Silva <https://github.com/perigoso>`__
-----------------------------------------------
-
--  Port DCD Synopsys to support Silabs EFM32GG12 with SLTB009A board
--  Rewrite documentation in rst and setup for readthedocs
--  Generalize Renesas driver and support RA family with EK-RA4M3 board
-
-
-`Raspberry Pi Team <https://github.com/raspberrypi>`__
-------------------------------------------------------
-
--  Add new DCD port for Raspberry Pi RP2040
--  Add new HCD port for Raspberry Pi RP2040
-
-
-`Reinhard Panhuber <https://github.com/PanRe>`__
-------------------------------------------------
-
--  Add new class driver for USB Audio Class 2.0 (UAC2)
--  Rework tu\_fifo with unmasked pointer, add DMA support, and constant address support
--  Add new DCD/USBD edpt\_xfer\_fifo() API for optimizing endpoint transfer
--  Add and greatly improve Isochronous transfer
--  Add new audio examples: audio\_test and audio\_4\_channel\_mic
-
-
-`Scott Shawcroft <https://github.com/tannewt>`__
-------------------------------------------------
-
--  Add new DCD port for SAMD21 and SAMD51
--  Add new class driver for Musical Instrument Digital Interface (MIDI)
--  Improve USBD control transfer, MSC, CDC class driver
--  Board support for Metro M0 & M4 express
--  Write the excellent porting.md documentation
--  Add initial Makefile
-
-`Sean Cross <https://github.com/xobs>`__
-----------------------------------------
-
--  Add new DCD port for ValentyUSB eptri (fomu board)
-
-
-`Sylvain "tnt" Munaut <https://github.com/smunaut>`__
------------------------------------------------------
-
--  Add new class driver for DFU Runtime
-
-
-`Tian Yunhao <https://github.com/t123yh>`__
--------------------------------------------
-
--  Add new DCD port for Allwinner F1C100S/F1C200S
--  Add support for osal_rtx4
-
-`Timon Skerutsch <https://github.com/PTS93>`__
-----------------------------------------------
-
--  Add hid\_test.js script and extensive test for bi-directional raw HID
-
-
-`Tod E. Kurt <https://github.com/todbot>`__
--------------------------------------------
-
--  Add hid\_test.js script and extensive test for bi-directional raw HID
-
-
-`Uwe Bonnes <https://github.com/UweBonnes>`__
----------------------------------------------
-
--  Improve STM32 Synopsys highspeed DCD
-
-
-`William D. Jones <https://github.com/cr1901>`__
-------------------------------------------------
-
--  Add new DCD port for Synopsys DesignWare for STM32 L4, F2, F4,
-   F7, H7 etc ...
--  Add new DCD port for TI MSP430
--  Board support for STM32F407 Discovery, STM32H743 Nucleo, pyboard v1.1, msp\_exp430f5529lp etc ...
-
-
-`Zixun Li <https://github.com/HiFiPhile>`__
--------------------------------------------
-
--  Add new DCD port for Microchip SAMx7x
--  Add IAR compiler support
--  Improve UAC2, CDC, DFU class driver
--  Improve stm32_fsdev, chipidea_ci_hs, lpc_ip3511 DCD
--  Host IAR Build CI & hardware in the loop (HITL) test
-
-
-`Full contributors list <https://github.com/hathach/tinyusb/contributors>`__
-============================================================================