[IMP] doc: add i18n section to command line reference

Closes #14042

doc/reference/cmdline.rst

@@ -156,6 +156,45 @@ database
     when creating new databases from the database-management screens, use the
     specified `template database`_. Defaults to ``template1``.
 
+.. _reference/cmdline/server/internationalisation:
+
+Internationalisation
+--------------------
+
+Use these options to translate Odoo to another language. See i18n section of
+the user manual. Option '-d' is mandatory. Option '-l' is mandatory in case
+of importation
+
+.. option:: --load-language <languages>
+
+    specifies the languages (separated by commas) for the translations you
+    want to be loaded
+
+.. option:: -l, --language <language>
+
+    specify the language of the translation file. Use it with --i18n-export
+    or --i18n-import
+
+.. option:: --i18n-export <filename>
+
+    export all sentences to be translated to a CSV file, a PO file or a TGZ
+    archive and exit.
+
+.. option:: --i18n-import <filename>
+
+    import a CSV or a PO file with translations and exit. The '-l' option is
+    required.
+
+.. option:: --i18n-overwrite
+
+    overwrites existing translation terms on updating a module or importing
+    a CSV or a PO file.
+
+.. option:: --modules
+
+    specify modules to export. Use in combination with --i18n-export
+
+
 built-in HTTP
 -------------