Return only the unique keymaps

Drop bs4 dependency, update docs, minor improvements

Fix regex for parsing rules.mk files

I don't know why it couldn't put it together before... ¯\_(ツ)_/¯

Add test for list_keymaps

Another major refactoring, add documentation

Move all useful functions to the qmk module and use the cli subcommand
as a wrapper around it.
Add both inline comments and documentation.

Fix output format

Try to figure out revision, drop -rv/--revision argument

Fix help message.

Get all buildable keymaps for each revision

The command now return all keymaps that's buildable for a
keyboard/revision. If the base directory of a keyboard does not contain
a 'rules.mk' file, nothing is returned. If the base directory contains a
'keymaps' directory, those keycaps will be returned for every revision.

Major update to work better with revisions

Find the community keymaps supported by each revision.

Add bs4 to requirements.txt

UnicodeDammit is needed from bs4 for reading files.

CLI: add support for list_keymaps

List all the available keymaps for a given keyboard

Adding VIA support for 40percentclub/luddite (#8158)

* Adding VIA support for 40percentclub/luddite

* Update config.h

* Update rules.mk

* Delete config.h

config.h was created to override the "default" of RGBLED_NUM 8
deleting the file to keep with defaults

* Removing block and comment as suggested

* Update PRODUCT_ID

Changing from:

 #define PRODUCT_ID      0x0A0C 

To:

 #define PRODUCT_ID      0x4C55 // "LU"

* Changing Vendor ID

Changing Vendor ID from:
#define VENDOR_ID       0xFEED
To:
#define VENDOR_ID       0x3430 // "40"

[keymap] Update audio controls on community (#8163)

* Update audio controls on community

* Add rules for various boards

* TKL support

Just60 Configurator layout support and thinxer keymap (#7761)

* Just60 Configurator layout support

* adds thinxer keymap, which is the default keymap with QMK DFU bootloader

Add community layout support to Mysterium (#8164)

Convert two handwired default keymaps to Dynamic Macro feature (#8166)

[osx_neo2] Bugfixes and improvements to Ergodox macOS Neo2 keymap (#8154)

* Use TAPPING_TERM constant (and redefine value to 200ms)
* change TAPPING_TOGGLE to 2 to require two taps to lock in layer 4
* add support for Shift-Command 3/4/5 key combinations that are used in
  macOS Catalina
* avoid false positive tap detecion for RMOD3 when the whole sequence of
  pressing RMOD3, tapping another key and releasing RMOD3 took less than
  TAPPING_TERM milliseconds.
* replace SEND_STRING with tap_code()/tap_code16(), saving ~860 bytes in
  compiled firmware size.

[Keymap] Add personal keymap (#7338)

* Copy default config
* Copy and edit Preonic keymap layers
* Update README

format code according to conventions [skip ci]