Core list: sortable columns, notes filled in, cores not on the buildbot removed

[WizzardSK]

Three changes to the Core List:

• Sortable tables. A click on a column header sorts the table by that column, a second click reverses it. This is Material for MkDocs' own recipe (data tables, sortable): tablesort 5.3.0 from unpkg and a four-line script in docs/javascripts/tablesort.js. It applies to every plain table on the site, not only this one.
• Notes filled in. 140 of the 143 empty Notes cells now hold the first sentence of the core's description from the buildbot's info.zip. Frodo, Potator and Redream have no description there and stay empty. GAM4980's row also gets its missing closing pipe.
• Cores removed that the buildbot does not build: bnes, Citra Canary, Dungeon Crawl Stone Soup, Emux CHIP-8, Emux GB, Emux NES, Emux SMS, FreeJ2ME, FreeJ2ME-Plus, Imageviewer, mGBA Splitscreen, mkxp-z, Picocomputer 6502, RVVM, TempGBA, VICE x64dtv, ZEsarPCW. None of them is in the nightly folders of any platform, although some have an info file. Their library pages are left as they are.

Built locally with mkdocs 1.6.1 and Material 9.7.7; sorting tried on the built page.