enable trigger github actions manually (#3)

.github/workflows/lint-test.yaml

@@ -1,6 +1,12 @@
 name: Lint and Test Charts
 
-on: pull_request
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'charts/**'
+  workflow_dispatch: {}
 
 jobs:
   lint-test:

.github/workflows/release.yaml

@@ -1,9 +1,7 @@
 name: Release Charts
 
 on:
-  push:
-    branches:
-      - main
+  workflow_dispatch: {}
 
 jobs:
   release:

README.md

@@ -15,6 +15,7 @@ Once Helm is set up properly, add the repo as follows:
 helm repo add openyurt https://openyurtio.github.io/charts
 ```
 
+If you have already added this repo earlier, run `helm repo update` to retrieve the latest versions of the packages.
 You can then run `helm search repo openyurt` to see the charts.
 
 ### Install `yurt-manager`