Use correct icon url and use a generic maintainer section

Signed-off-by: Marco Kilchhofer <mkilchhofer@users.noreply.github.com>

charts/argocd-image-updater/Chart.yaml

@@ -5,15 +5,14 @@ type: application
 version: 0.1.0
 appVersion: v0.10.1
 home: https://github.com/argoproj-labs/argocd-image-updater
-icon: https://raw.githubusercontent.com/argoproj/argo/master/docs/assets/argo.png
+icon: https://argocd-image-updater.readthedocs.io/en/stable/assets/logo.png
 keywords:
   - argoproj
   - argocd
   - gitops
 maintainers:
-  - name: alexec
-  - name: alexmt
-  - name: jessesuen
+  - name: argoproj
+    url: https://argoproj.github.io/
 annotations:
   artifacthub.io/changes: |
     - "[Added]: First chart release"