Rewrite /scope:.+/<URL> to just <URL>

Related to WordPress/wordpress-playground#42

This commit implements the URL rewrite with:

* A liveServer middleware for local dev
* A .htaccess file for apache production setups

Documenting this behavior in a visible place will be critical for mass
adoption of this project.

Nested iframes with src="about:srcdoc" are not controlled by the
parent's frame ServiceWorker. This is a bug in Chrome and potentially
other Chromium-based browser.

This is problematic because WordPress site editor is rendered in one
such iframe and it loads a bunch of stylesheets using a link tag like:

    <link rel="stylesheet" href="/scope:<scope>/<URL>" />

The /scope:<scope>/ part of the URL does not actually exist on the
server – it's a WordPress instance scope introduced to make WASM
WordPress usable in multiple browser tabs. Learn more at WordPress/wordpress-playground#31

The point is – these stylesheet requests bypass the ServiceWorker and
are actually sent to the server where they get a 404 response. This
effectively breaks the site editor.

We cannot re-route these requests in a ServiceWorker, but we can do it
on the server. That's what this commit is.

Unfortunately this commit won't solve the problem in setups based on nginx
and other server software – let's follow it up with a documentation
update.

dist-web/.htaccess

@@ -0,0 +1,4 @@
+AddType application/wasm .wasm
+
+RewriteEngine on
+RewriteRule ^scope:.*?/(.*)$ $1 

liveServer.js

@@ -0,0 +1,22 @@
+const liveServer = require('live-server');
+
+liveServer.start({
+	port: 8777,
+	root: __dirname + '/dist-web',
+	open: '/wordpress-browser.html',
+	file: 'wordpress-browser.html',
+	middleware: [
+		(req, res, next) => {
+			if (req.url.startsWith('/scope:')) {
+				req.url = '/' + req.url.split('/').slice(2).join('/');
+			}
+			next();
+		},
+	],
+});
+
+liveServer.start({
+	port: 8778,
+	root: __dirname + '/dist-web',
+	open: false
+});

package.json

@@ -8,8 +8,7 @@
     "dev:web": "npm-run-all --parallel dev:web:*",
     "dev:web:app": "npm run build:web:app -- --watch",
     "dev:web:html": "chokidar --initial --silent \"./src/web/*.html\" -c \"cp src/web/*.html dist-web/\"",
-    "dev:web:serve": "npx live-server ./dist-web --port=8777 --open=wordpress.html",
-    "dev:web:serve-iframe-worker": "npx live-server ./dist-web --port=8778 --no-browser",
+    "dev:web:serve": "node liveServer.js",
     "dev:node": "node ./src/node/command.mjs",
     "build": "npm run build:web",
     "build:web": "npm-run-all --parallel build:web:*",