add support for m65 a simple 5x13 ortholinear

[alinelena]

Description

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[zvecr]

Also required, GPL compatible licence headers on all .h and .c files

[sigprof]

Are the ChibiOS config needed here at all? Apparently this keyboard does not even use PWM for backlight or anything else, and USART is also not actually used; if these options come from another keyboard used as a template, they can be removed.

[tzarc]

Sorry about that, GitHub decided to delete the develop branch from upstream when we merged it, despite being told otherwise. Reopened.

[liyang]

I agree with @sigprof here https://github.com/qmk/qmk_firmware/pull/12012/files#r583111072

Individual keymaps shouldn't have to know which pins are connected to what—these should be abstracted away on the keyboard level.