Update readme with github action instructions

Author: benrowe

README.md

@@ -1,11 +1,26 @@
-# MySQL to SQLite3 (Docker)
+# MySQL to SQLite3 (Docker + Github action)
 
 Implements [MySQL to SQLite3][link-sql] as a docker utility
 
-## How to use
+## How to use as docker
 
 ```
-docker run --rm -v ${PWD}:/output benrowe/mysql-to-sqlite3 mysql2sqlite -f /output/export.sqlite3 -d database_name -u username -h host.docker.internal -p password
+docker run --rm -v ${PWD}:/output benrowe/mysql-to-sqlite3 database_name username host.docker.internal password path/to/file
+```
+
+## How to use as github action
+
+The github action runs this command inside the docker file, so the host will need to point to the host machien
+
+```
+- name: Convert to SQLite
+  uses: benrowe/mysql-to-sqlite3-docker@v1
+  with:
+    output: /path/to/file
+    database: database
+    host: localhost
+    username: root
+    password: password
 ```
 
 [link-sql]:https://github.com/techouse/mysql-to-sqlite3