Internals: Make the extensions gallery deployment origin configurable

[boswellfox]

Note

You can see the original issue made on my TurboWarp Docker project here for additional context on why this issue was made, or if I did not properly explain something in this issue.

The production build of the extension gallery website currently generates extension, documentation, and sample URLs with https://extensions.turbowarp.org/, which is hard-coded. For DX, you could make the deployment origin configurable instead of hard-coded.

Possible Solution

Here is how you could solve this issue:

1. The default remains https://extensions.turbowarp.org/.
2. The production build uses the configured origin for generated gallery pages, extension URLs, documentation URLs, sample URLs, and sitemap URLs.
3. The build rewrites only generated output when necessary. It should not require contributors to change every source URL.
4. The deployment origin must use https: in production.
5. The build normalizes the origin so it has one trailing /.

[GarboMuffin]

you can submit that

[boswellfox]

you can submit that

Done. #2656 will close this issue.