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/gitea/Chart.yaml

@@ -15,7 +15,7 @@ dependencies:
 deprecated: false
 description: Self hosted GIT repositories
 home: https://github.com/truecharts/apps/tree/master/charts/stable/gitea
-icon: https://truecharts.org/_static/img/appicons/gitea-icon.png
+icon: https://truecharts.org/_static/img/appicons/gitea.png
 keywords:
 - git
 - issue tracker