chore: add readme example

README.md

@@ -1 +1,29 @@
 # release
+
+```yaml
+uses: actions/release:1.0.0
+with:
+  # The owner and repository name seperated by a slash of the repository in which
+  # the release should be created. The repository must be on the same instance as
+  # the action is running on.
+  repository: ${{ github.repository }}
+  # The tag name of the git tag for which the release should be created and to
+  # which the artifacts should be attached to.
+  version: ${{ github.ref_name }}
+  # A boolean value or a regex pattern which will be evaluated against the version
+  # to determine if the created release will be saved as draft.
+  draft: false
+  # A boolean value or a regex pattern which will be evaluated against the version
+  # to determine if the created release will be marked as pre-release.
+  prerelease: false
+  # The label of the created release. Leave this empty to use the label of the
+  # referenced git tag.
+  label:
+  # The message of the created release. Leave this empty to use the notes of the
+  # referenced git tag.
+  notes:
+  # Paths to files which will be attached to the release. Can be multiple lines
+  # with file system globbing patterns. A line starting with ! will negate the
+  # pattern and act as exclude pattern.
+  attachments:
+```

github.go

@@ -44,7 +44,7 @@ func NewGitHub(client ApiClient) *GitHub {
 }
 
 func HasContentType(r *http.Response, mimetype string) bool {
-	contentType := r.Header.Get("Content-type")
+	contentType := r.Header.Get("content-type")
 	if contentType == "" {
 		return mimetype == "application/octet-stream"
 	}