This PR cleans up the docs in a way to make them simpler to ingest by
our [docs repo](https://gitea.com/gitea/gitea-docusaurus).
1. It includes all of the sed invocations our ingestion did, removing
the need to do it at build time.
2. It replaces the shortcode variable replacement method with
`@variable@` style, simply for easier sed invocations when required.
3. It removes unused files and moves the docs up a level as cleanup.
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Signed-off-by: jolheiser <john.olheiser@gmail.com>
After RPM is supported with https://github.com/go-gitea/gitea/pull/23380
let's show the user
how to add the repo and install the RPM via all common package managers.
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Co-authored-by: Giteabot <teabot@gitea.io>
