Update the memory consumption of PREVENT_STUCK_MODIFIERS in README

Cut the memory consumption of PREVENT_STUCK_MODIFIERS in half

Expose the pressed_actions_cache global variable

Always provide an implementation of process_action_nocache

process_action may be called either with key cache or without it

If one wants to temporarily disable the key cache (for example because
it interferes with a macro), `disable_action_cache` must be set to
`true`. `process_action_nocache` is a simple wrapper doing just that for
a single call.

Document the issue of stuck modifiers

Fix the layer-dependent modifiers handling

Closes #181.

Merge pull request #180 from NoahAndrews/add-build-instructions

Added build instructions to BUILD_GUIDE.md

Added build instructions to BUILD_GUIDE.md

Merge pull request #179 from NoahAndrews/add-win-linux-instructions

Added Windows and Linux instructions to BUILD_GUIDE.md

Added Windows and Linux instructions to BUILD_GUIDE.md

Merge pull request #176 from NoahAndrews/fix-new-projects

Fix building new projects

Remove extraneous comma

Merge pull request #171 from NoahAndrews/restructure-documentation

Restructure documentation

Merge pull request #170 from NoahAndrews/improve-windows-docs

Add scripts for easy Windows environment setup

Merge pull request #165 from deepshitgoeshere/deepshitgoeshere-master

added planck keymap and troubleshooting part in the PCB guide

Merge pull request #175 from NoahAndrews/fix-#174

Fix #174

Fix #174

Merge pull request #172 from plgruener/pr1

add missing keys to keymap_neo2.h

update neo keymap