Site reorg: Remove site/ subpath (#306)

Unfortunately, for proper package pathing, need to remove the `site/`
subpath. This includes:
- Moving everything back into root
- Adding a `copy-site.sh` script to copy resources into `mkdocs/site/`
before building the site with mkdocs.
- Also update examples to ensure all are loading the local sw.js / ui.js
- Consolidate examples in `docs/examples`
- Consolidate assets under src/assets/
- Move `favicons` to root
- Reformat and relint
- Tests: update playwright tests to use mkdocs output, add test for
embed in docs
- bump to 2.0.0-beta.2

.eslintrc.js

@@ -103,10 +103,11 @@ module.exports = {
   ignorePatterns: [
     "__generated__",
     "__mocks__",
+    "mkdocs/_genhtml",
     "dist",
     "ruffle",
-    "ui.js",
-    "sw.js",
+    "**/ui.js",
+    "**/sw.js",
   ],
   overrides: [
     {