Rename develop -> development, contribute -> contributing, administer -> administration (#23662)

backport #23629 

To make versioned documentation less surprising, 1.19 should have the
same technology.

doc/contributing/localization.en-us.md

@@ -0,0 +1,33 @@
+---
+date: "2016-12-01T16:00:00+02:00"
+title: "Localization"
+slug: "localization"
+weight: 10
+toc: false
+draft: false
+menu:
+  sidebar:
+    parent: "contributing"
+    name: "Localization"
+    weight: 20
+    identifier: "localization"
+---
+
+# Localization
+
+Gitea's localization happens through our [Crowdin project](https://crowdin.com/project/gitea).
+
+For changes to an **English** translation, a pull request can be made that changes the appropriate key in
+the [english locale](https://github.com/go-gitea/gitea/blob/master/options/locale/locale_en-US.ini).
+
+For changes to a **non-English** translation, refer to the Crowdin project above.
+
+## Supported Languages
+
+Any language listed in the above Crowdin project will be supported as long as 25% or more has been translated.
+
+After a translation has been accepted, it will be reflected in the main repository after the next Crowdin sync, which is generally after any PR is merged.
+
+At the time of writing, this means that a changed translation may not appear until the following Gitea release.
+
+If you use a bleeding edge build, it should appear as soon as you update after the change is synced.