build(learn): the F-Droid repository keeps the kingfisher as its icon

The repository is all of Halkyon's apps', so its icon stays Halkyon's
emblem (ADR 0031, D3), kept in tool/release/fdroid/ now that the snap's
icon is Learn's graduation cap. Learn's listing keeps the snap's.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

tool/release/fdroid/config.yml

@@ -12,7 +12,9 @@ repo_description: >-
 archive_name: Halkyon (archive)
 archive_description: >-
   Older versions of Halkyon's apps.
-# The snap's icon, which tool/fdroid_repo.sh copies beside this file.
+# The kingfisher, Halkyon's emblem, on a white tile with rounded corners (the snap's
+# icon until Learn's became the graduation cap, ADR 0031, D3): the repository is all
+# of Halkyon's apps', not Learn's.
 repo_icon: halkyon.png
 archive_icon: halkyon.png
 # The newest three versions of each app stay in the repository, older ones move