docs: Move translation docs to handbook (bis)

Author: jpmckinney

crowdin.yml

@@ -122,11 +122,6 @@
       "dest": "contributing/indicators/test.pot",
       "translation": "/docs/locale/%two_letters_code%/LC_MESSAGES/contributing/indicators/test.po"
     },
-    {
-      "source": "/docs/_build/gettext/contributing/translation.pot",
-      "dest": "contributing/translation.pot",
-      "translation": "/docs/locale/%two_letters_code%/LC_MESSAGES/contributing/translation.po"
-    },
     {
       "source": "/docs/_build/gettext/index.pot",
       "dest": "index.pot",

docs/contributing/index.md

@@ -35,5 +35,4 @@ We can consider the [criterion](https://crates.io/crates/criterion) crate for ad
 :maxdepth: 1
 
 indicators/index
-translation
 :::