Updates to noroadsleft keymap for KC60 (#5127)

Updates to noroadsleft keymap for KC60 (#5127)

* NUBS_Z: initial version

Create a keycode that is normally Z, but KC_NUBS when tapped while Alt is being held.

This removes the possibility of using an Alt+Z shortcut.

* NUBS_Z: modification

Modify NUBS_Z macro to only use alternate operation if Right Alt is being held, rather than responding to either Alt key.

Also add QMK version keycode to System layer, Equals key.

* Remove unneeded breaks from process_record_user

* Macro refactoring

- removed G_RST and G_C10R macros
- updated G_BRCH macro
  - outputs `master` if used while Shift is held down; or my git alias for the current branch otherwise
- updated G_FTCH macro
  - outputs `git pull upstream ` if used with Shift; `git fetch upstream ` otherwise
- swapped `modifiers` variable for `get_mods()` function directly for checking modifier state
- swapped keymap-level modifier mask macros for QMK-core mod mask macros (thanks vomindoraan #4337)
- renamed MODS_RALT_MASK to MOD_MASK_RALT (more consistent with the above change)

* Update readme files