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>

site/docs/index.md

@@ -0,0 +1,39 @@
+---
+hide:
+    - navigation
+    - toc
+---
+
+# Home
+
+Welcome to the ReplayWeb.page documentation! These docs contain the following sections:
+
+- [User Guide](user-guide/index.md) — Introduction and reference for using ReplayWeb.page to view archived web content.
+- [Embedding Docs](develop/embedding.md) — Information on integrating and embedding ReplayWeb.page as a web archive viewer into existing web sites.
+
+## What is ReplayWeb.page?
+[ReplayWeb.page](https://replayweb.page) is an open-source, browser-based viewer that loads and renders static web archive files. It functions as a serverless (client side) replay tool that _doesn't_ require a server to coordinate what archived content should be retrieved from a large central repository. It allows web archives to be hosted on any regular web server and viewed in any modern browser.
+
+### Key Features
+
+- High-fidelity replay of archived items in several formats.
+- Page search and URL search.
+- Full text search support for archived items that include extracted text.
+- On-demand, incremental loading of large files.
+- Several options for fully-functional offline usage, including a standalone desktop app with Flash support.
+- Support for embedding archived items directly into your website!
+
+### Archives, Repositories, and Other Projects Using ReplayWeb.page
+
+ReplayWeb.page allows web archives seamlessly integrate into existing web sites, be it repositories, collections, or other archiving services.
+
+Below are a few of the integrations we know of that use ReplayWeb.page:
+
+- [Perma.cc](https://archive.blogs.harvard.edu/perma/2022/08/17/new-playback-software-improves-fidelity-of-your-perma-links/) — Web archiving service offered by Harvard's Library Innovation Lab.
+- [GhostArchive](https://ghostarchive.org/) — Free Web Archiving Service
+- [The Feminist Institute](https://www.thefeministinstitute.org/digital-archive/archived-websites) — Websites archived to document and celebrate feminist contributions to culture.
+- [CineFiles](https://cinefiles.bampfa.berkeley.edu/?f%5Bdoctype_s%5D%5B%5D=web+archive) — Film-related web archive ephemera collected by the UC Berkeley Art Museum and Pacific Film Archive.
+- [Stanford Digital Publication Web Archives](https://archive.supdigital.org/) — Archives of Stanford University Press Digital Publications.
+- [ysdn.info](https://ysdn.info/) — Final year grad show websites from the now defunct York / Sheridan design program.
+
+If you know of any additional sites that you'd like us to include here, let us know by writing to _info_ [at] _webrecorder.net_