massive update wiki
Document sign_write/sign_read, entities, rs_pulse, realtime, and the Memory Card item
added inventory management wiki
Updated Home (markdown)
Rename landing page back to Home.md GitHub wikis only treat a page literally named 'Home' as the default landing page. Renaming it to 'PotScript Wiki' broke that, so every other page's back-link and the sidebar's top link stopped resolving to a real landing page. Restore the Home slug and its H1 heading.
Split docs into separate wiki pages with nav sidebar Replace the single-page stub Home.md with a proper landing page and split the PotScript reference into Quickstart, Language Guide, Execution Model, Standard Library, Errors & Gotchas, and Examples.
Initial Home page