Add support for MyMakers RP2040 board

[nui4328]

Summary

This PR adds support for the custom MyMakers RP2040 board.

Changes

1. Added a new entry in boards.txt for the MyMakers RP2040 board.
2. Created a new folder variants/mymakers_rp2040 containing:
   • pins_arduino.h: Pin definitions for the MyMakers RP2040 board.
   • variant.cpp: Additional variant configuration.
3. Updated documentation to guide users on how to use the new board.

Testing

• Compiled and uploaded a basic "Blink" sketch to the MyMakers RP2040 board.
• Verified GPIO functionality and pin mappings for digital and analog I/O.

Notes

• Please review the pin definitions in pins_arduino.h to ensure compatibility.
• Future work: Add support for additional features such as I2C and SPI peripherals.

[earlephilhower]

This loses the recent board.mcu change. Can you rebase off of latest and try again?

[earlephilhower]

This still is broken and throws out some important changes that were done to makeboards.py. Check the "Files Changed" link at the top of the PR to see.

Also, is this a generally available board or your own creation? I can't find any documentation on it online.

[nui4328]

It's a board that I developed myself. In the past I chose to use it under the name of the raspberry Pi Pico board.

[earlephilhower]

Err, the latest push shows the entire boards.txt file has been munged. Not sure if you've hand-edited things or the line endings have been broken, but it's not going to work...
33,109 additions, 32,873 deletions not shown because the diff is too large. Please use a local Git client to view these changes.

It's a board that I developed myself. In the past I chose to use it under the name of the raspberry Pi Pico board.

I'm sorry, but if this is something that's not going to be "out in the wild" and available to others, I really can't pull it in to the core. Something like that would be a good use of a personal fork of the repo, or just using the generic as appropriate.

[nui4328]

It's a board that I developed myself. In the past I chose to use it under the name of the raspberry Pi Pico board.
used for education Student robot control programming and is used in public places Boards are distributed for others to use.

[earlephilhower]

This is still broken badly. Please be sure you've merged with master and re-run makeboards and not touched the boards.txt file. When you push, please check the "files changed" tab ans if you see 30,000+ lines differing in boards.txt, there is still a problem...

1. All the endlines are busted. The script makes it UNIX format, even on Windows, but somehow this PR has it \r\n
2. The boards.txt seems to have deleted TONS of boards, Profiling, and other bits of the core.