Feat/theme switcher blacksky

[grishaLR]

overview

Note

the massive diff is from: @atproto/common-web missing for me locally so i added it. also ended up generating a full lockfile. will follow your lead on how you'd like to resolve these

this closes issue #9 supporting themes - after this PR everything is in place for anyone to cut a PR to add a theme!!

this PR brings in Blacksky theme and a theme switcher! woohoo! adds instructions for how to contribute

on thing to note: @atproto/common-web was missing and broke the events tab so i added that

description

pretty straight forward!

• renames CSS var --border to --border-color
• adds contributing docs
• adds theme switcher dropdown
• adds Blacsky theme
• adds missing dep @atproto/common-web that broke the page when navigating to/communities

09:19:10 [ERROR] Cannot find module '@atproto/common-web' imported from '/Users/grisha/code/atproto-community/src/lib/rsvps.ts'
  Stack trace:
    at fetchModule (file:///Users/grisha/code/atproto-community/node_modules/.pnpm/vite@7.3.3_yaml@2.8.4/node_modules/vite/dist/node/chunks/config.js:34000:34)
    at fetchModule (file:///Users/grisha/code/atproto-community/node_modules/.pnpm/vite@7.3.3_yaml@2.8.4/node_modules/vite/dist/node/chunks/config.js:34810:17)
    at EventEmitter.listenerForInvokeHandler (file:///Users/grisha/code/atproto-community/node_modules/.pnpm/vite@7.3.3_yaml@2.8.4/node_modules/vite/dist/node/chunks/config.js:25908:19)
    at Object.send (file:///Users/grisha/code/atproto-community/node_modules/.pnpm/vite@7.3.3_yaml@2.8.4/node_modules/vite/dist/node/chunks/config.js:15068:39)
    at Object.invoke (file:///Users/grisha/code/atproto-community/node_modules/.pnpm/vite@7.3.3_yaml@2.8.4/node_modules/vite/dist/node/module-runner.js:584:31)
09:19:35 Configuration file updated. Restarting...
[vite] connected.

screengrabs

blacksky-themeswitcher.mp4

[grishaLR]

@essential-randomness should i remove the lockfile? i was surprised by this addition...

[grishaLR]

unsure how this diverged... the /communites page broke for me locally but is working in production 🤔