Add Documentation for swag-fmt Hook

Author: muya

README.md

@@ -1,2 +1,38 @@
 # pre-commit-swaggo
-Pre-commit hooks for Go projects using https://github.com/swaggo/swag
+
+[pre-commit](https://pre-commit.com/) hooks for Go projects using https://github.com/swaggo/swag
+
+## Usage
+
+Add this to your `.pre-commit-config.yaml` file:
+
+```yaml
+repos:
+  # ... other repos ...
+  - repo: https://github.com/muya/pre-commit-swaggo
+    rev: "main"
+    hooks:
+      - id: swag-fmt
+```
+
+Arguments to `swag` can be passed as `args`.
+
+For example, to pass the `--exclude` flag to `swag fmt`:
+
+```yaml
+repos:
+  # ... other repos ...
+  - repo: https://github.com/muya/pre-commit-swaggo
+    rev: "main"
+    hooks:
+      - id: swag-fmt
+        args:
+          - --exclude ./a/special/file.go
+```
+
+## Available Hooks
+
+All of these hooks require [swaggo/swag](https://github.com/swaggo/swag#getting-started) to be installed, and available
+in your `$PATH`.
+
+- `swag-fmt` - Runs `swag fmt` on all files in the project.