📝 Update README

README.md

@@ -9,7 +9,30 @@ This library runs with GitHub Actions. If you feel that the example grammar belo
 
 ## Usage
 
-TBD
+I think the most common use is to visualize the results of CI execution, and here's an example.
+
+```yaml
+  test: # make sure the action works on a clean machine without building
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v3
+      - uses: marocchino/checkbox-action@v1
+        with:
+          list: 'test ok'
+          action: 'uncheck'
+          error: 'warn'
+      - run: |
+          yarn
+      - run: |
+          yarn all
+      - uses: marocchino/checkbox-action@v1
+        with:
+          list: 'test ok'
+          action: 'check'
+          error: 'warn'
+```
 
 ## Inputs
 
@@ -29,7 +52,7 @@ Regular expression for the checkbox to modify.
 
 ### `error`
 
-**Optional** error, warn or ignore. Specifies whether to skip or raise an error when error occurred. This defaults to error
+**Optional** error, warn or ignore. Specifies whether to skip or raise an error when not found. This defaults to error
 
 ### `GITHUB_TOKEN`