add README docs

README.md

@@ -1 +1,41 @@
 # GitHub Releases Resource
+
+Fetches and creates versioned GitHub resources.
+
+## Source Configuration
+
+* `access_token`: *Required.* The GitHub access token that should be used to
+  access the API.
+
+* `user`: *Required.* The GitHub username or organization name for the
+  repository that the releases are in.
+
+* `repository`: *Required.* The repository name that contains the releases.
+
+## Behavior
+
+### `check`: Extract versions from the bucket.
+
+*TODO*
+
+### `in`: Fetch an object from the bucket.
+
+*TODO*
+
+### `out`: Upload an object to the bucket.
+
+Given a name specified in `name`, a body specified in `body`, and the tag to use
+specified in `tag`, this creates a release on GitHub then uploads the files
+matching the patterns in `globs` to the release.
+
+#### Parameters
+
+* `name`: *Required.* A path to a file containing the name of the release.
+
+* `tag`: *Required.* A path to a file containing the name of the Git tag to use
+  for the release.
+
+* `body`: *Optional.* A path to a file containing the body text of the release.
+
+* `globs`: *Optional.* A list of globs for files that will be uploaded alongside
+  the created release.