Add notes to user/admin areas about translation basics (#1830)

Author: mjankowski

content/en/admin/config.md

@@ -772,11 +772,20 @@ Prefix for the OTEL service names. The services names will be `$prefix/web` and
 
 What character to use in service names when differentiating between different services. Defaults to `/` (i.e. `mastodon/web`).
 
-
 #### `OTEL_EXPORTER_OTLP_ENDPOINT`
 
 URL of the OLTP server to send the traces to. OpenTelemetry instrumentation is disabled if this variable is not set. No default (empty value).
 
+### Translation services {#translation}
+
+Mastodon supports integration with [DeepL] and [LibreTranslate] as backend language translation engines. Both services require separate setup and for configuration of Mastodon (via environment variables) to understand how to use them.
+
+- DeepL needs `DEEPL_API_KEY` and `DEEPL_PLAN` (defaults to "free")
+- LibreTranslate needs `LIBRE_TRANSLATE_API_KEY` and `LIBRE_TRANSLATE_ENDPOINT`
+
+[DeepL]: https://www.deepl.com
+[LibreTranslate]: https://libretranslate.com
+
 ## File storage {#files}
 
 ### CDN {#cdn}

content/en/user/network.md

@@ -125,3 +125,7 @@ Opening a list will load that list's timeline. List timelines contain only posts
 ## Syndication Feeds {#syndication}
 
 Every account and tag page provide an RSS feed for syndication onto other platforms. Those feeds are auto-discoverable from the account and tag pages.
+
+## Translation
+
+When a post is in a language other than what your account is set to understand, a "Translate" button will appear next to the post content. Clicking this button issues a request to translate the content to the server, and will replace that content with translated results. This feature requires the server to have configured support for a translation service, and so may not be available on all servers.