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

playwright.config.js

@@ -4,7 +4,7 @@ export default defineConfig({
   reporter: process.env.CI ? "github" : "list",
   webServer: [
     {
-      command: "yarn run start-prod",
+      command: "yarn run start-docs-prod",
       url: "http://127.0.0.1:9990",
       timeout: 120 * 1000,
       reuseExistingServer: !process.env.CI,