Canonical domain for books

[markhildreth]

For each book, there are a variety of URLs that can be used to access some version of the book. For example, the discovery book can be "found" under the following URLs:

• https://docs.rust-embedded.org/discovery/
• https://rust-embedded.github.io/discovery/

Since rust-embedded/wg#208, the goal has been to host them all under docs.rust-embedded.org. However, there are inconsistencies, which in some cases cause poor SEO, in others can confusion and updated content to never reach users. I have tried to find these problems that are easy to fix and list them in one place, creating and/or linking to issues to any issues that should be resolved.

Discovery Book

Canonical URL: https://docs.rust-embedded.org/discovery/
Repo: https://github.com/rust-embedded/discovery

• Canonical URL points to latest version found in repo (Automate process of building docs for docs.rust-embedded.org wg#457)
• GitHub repo links to canonical URL (Change the link to the rendered book in GitHub repo description? discovery#146)

Embedded Book

Canonical URL: https://docs.rust-embedded.org/book/
Repo: https://github.com/rust-embedded/book

• Canonical URL points to latest version found in repo (Automate process of building docs for docs.rust-embedded.org wg#457)
• GitHub repo links to canonical URL (Change the link to the rendered book in GitHub repo description? book#93)

Embedonomicon

Canonical URL: https://docs.rust-embedded.org/embedonomicon/
Repo: https://github.com/rust-embedded/embedonomicon

• Canonical URL points to latest version found in repo (Automate process of building docs for docs.rust-embedded.org wg#457)
• GitHub repo links to canonical URL

Additional Info

Currently, links using the correct domain might still use different paths, such as...

• https://docs.rust-embedded.org/xxx
• https://docs.rust-embedded.org/xxx/
• https://docs.rust-embedded.org/xxx/index.html

I'm not too worried about these for now, but it might be nice to have a better canonical link system. See rust-lang/mdBook#1238 for more.