* Docs: rename form checks page to "Checks / radios"
it's not immediately obvious that "checks" includes information about both checkboxes and radio buttons. while "checks / radios" is also still not perfect (as honestly even I didn't quite grok that "checks" meant checkboxes), it should make it slightly more obvious nonetheless
- Broke up existing theming page into separate pages
- Audited and updated each new docs page (some pages include some TBD sections)
- Update sidenav to reflect changes
- Fix links that pointed to the old Theming page
- Update docs styles to reflect recent changes
- Rewrite some bits in the Migration page
- Breaks grid content across multiple pages
- Updates mentions of grid tiers from five to six
- Rewrites how it works sections to reference new options and tiers
* Add utility class for the user-select property
* Docs: Add new page for behavior utility classes - includes user select utility
* Update and rename behaviors.md to interactions.md
* Update sidebar.yml
Co-authored-by: Mark Otto <otto@github.com>
Co-authored-by: XhmikosR <xhmikosr@gmail.com>
Co-authored-by: Martijn Cuppens <martijn.cuppens@gmail.com>
