chore(docs): Remove -icon string from icon png's (#2040)

* rename icons (remove `-icon`)

* Remove (`-icon`) from chart.yaml

* Add 2 icons

* slight format change

* remove -icon

charts/stable/firefox-syncserver/Chart.yaml

@@ -6,7 +6,7 @@ name: firefox-syncserver
 description: This is an all-in-one package for running a self-hosted Firefox Sync server.
 type: application
 home: "https://github.com/truecharts/apps/tree/main/charts/firefox-syncserver"
-icon: https://truecharts.org/_static/img/appicons/firefox-syncserver-icon.png
+icon: https://truecharts.org/_static/img/appicons/firefox-syncserver.png
 keywords:
   - server
   - sync