add files

README.md

@@ -1,2 +1,39 @@
 # go-hashfiles
 
+This action is to compute the SHA256 hash of specified files.
+
+**NOTE:** This action is written in Go. Please make sure the `runs-on` runner supports running Go actions.
+
+## Usage
+
+``` yml
+- uses: actions/go-hashfiles@v0.0.1
+  with:
+    # The working dir for the action.
+    # Default: ${{ github.workspace }}
+    workdir: ''
+
+    # The patterns used to match files.
+    # Multiple patterns should be seperated by `\n`
+    patterns: ''
+```
+
+## Output
+
+|Output Item|Description|
+|---|---|
+|hash|The computed hash result|
+|matched-files|The files matched by the patterns|
+
+## Example
+``` yml
+- uses: actions/go-hashfiles@v0.0.1
+  id: get-hash
+  with: 
+    patterns: |-
+      go.sum
+      ./admin/*
+      **/package-lock.json
+- name: Echo hash
+  run: echo ${{ steps.get-hash.outputs.hash }}
+```