add example

README.md

@@ -1,2 +1,12 @@
-# github-action-setup-xmake
+# GitHub Action - Setup xmake
 Set up your GitHub Actions workflow with a specific version of xmake
+
+## Usage
+
+See [action.yml](./action.yml).
+
+## Example
+
+uses: OpportunityLiu/github-action-setup-xmake@master
+with:
+  xmake-version: '2.2.8'

action.yml

@@ -8,4 +8,5 @@ inputs:
     description: The version to use. Should be a semver range or 'latest'
 runs:
   using: 'node12'
-  main: 'index.js'
+  main: 'index.js'
+