keycodes.md: don't use section headings as links
It prevents the Table of Contents from parsing that heading.
make sure all our redirects are in order
Add more call to action items
Add explicit id tags to externally linked headers
refactor How a Matrix Works doc
Hand Wire guide tidying, part 2
clean up Firmware Setup section in Hand Wire guide
remove collapsible section for Compiling; redirect to Building Firmware doc
replace QMK Toolbox image in Hand Wire guide
Showing a current version of QMK Toolbox
restructure Hand Wire Guide
split Hand Wire Preamble to a separate doc
CSS updates: ul and pre elements
Polish Configurator section
Adjust the H2 and H2 margins
reduce the line-height of the sidebar
rearrange the sidebar a bit
limit the TOC to H1 and H2
remove line drawing chars
make custom_keycode_names.md a faq entry instead