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/muximux/Chart.yaml

@@ -7,7 +7,7 @@ dependencies:
 description: A lightweight portal to view & manage your HTPC apps without having to
   run anything more than a PHP enabled webserver
 home: https://github.com/truecharts/apps/tree/master/charts/stable/muximux
-icon: https://truecharts.org/_static/img/appicons/muximux-icon.png
+icon: https://truecharts.org/_static/img/appicons/muximux.png
 keywords:
 - muximux
 - htpc