MKDocs conversion (#278)

Closes #252, Closes #250

## Changes
- ReplayWeb.page uses MKDocs for documentation now!
- Requires both
[`mkdocs-macros`](https://mkdocs-macros-plugin.readthedocs.io/en/latest/)
and [`mkdocs-redirects`]
(https://github.com/mkdocs/mkdocs-redirects) plugins to be installed
- Redirects existing docs pages to their new locations under either
`/embedding` or `/user-guide`
- Unused images have been removed
- Adds new ReplayWeb.page branding!

All pages have received copy edits. All references to future (or
previously) planned features have been removed. More major content
changes of note are as follows:

### Supported Locations
- Made into a page, no longer a table. Locations are either supported or
not listed.

### Offline Use 
- Removes browser cache section, adds improved PWA install and uninstall
instructions.
- Removes navigation instructions to GitHub's releases section in favour
of a link

### Supported Formats
- Moved to the User Guide homepage
- Updated the format support

### Exploring Archives
- Example links for showcasing features have been moved to their
respective feature documentation section on this page

### Remove Usage, Examples, and Troubleshooting Pages
- Usage content is covered in the user guide index
- Troubleshooting content has been added to a question section on the
getting started page about WARC vs WACZ.
- Examples are now Featured Projects on the docs homepage!

### Build Process
- Removes Jekyll & related site assets.
- Adds new GitHub action for publishing
- Adds a python macro to dynamically load the replayweb.page version from package.json
- Relocates replayweb.page site content under /site (including docs)
- Some assets (favicon, logo) and sw.js/ui.js automatically copied into /site

---------
Co-authored-by: Ilya Kreymer <ikreymer@gmail.com>

webpack.config.js

@@ -103,17 +103,25 @@ const browserConfig = (/*env, argv*/) => {
     ui: "./src/index.ts",
   };
 
-  const patterns = [{ from: "package.json", to: "_data/package.json" }];
+  //const patterns = [{ from: "package.json", to: "_data/package.json" }];
+  let patterns = [{
+    from: "build/icon.png",
+    to: "site/assets/favicon.png",
+  }, {
+    from: "assets/logo.svg",
+    to: "site/assets/logo.svg"
+  }];
 
   if (isDevServer) {
     entry["sw"] = "@webrecorder/wabac/src/sw.js";
   } else {
     patterns.push({
       from: "node_modules/@webrecorder/wabac/dist/sw.js",
-      to: "sw.js",
+      to: "site/sw.js",
     });
   }
 
+
   /** @type {import('webpack').Configuration} */
   const config = {
     target: "web",
@@ -129,7 +137,7 @@ const browserConfig = (/*env, argv*/) => {
 
     output: {
       path: path.join(__dirname),
-      filename: "[name].js",
+      filename: "dist/[name].js",
       libraryTarget: "self",
       globalObject: "self",
       publicPath: "/",
@@ -139,7 +147,7 @@ const browserConfig = (/*env, argv*/) => {
       compress: true,
       port: 9990,
       open: false,
-      static: path.join(__dirname),
+      static: path.join(__dirname, "site"),
       //publicPath: "/"
     },