update readme

README.md

@@ -1,3 +1,21 @@
 # Excalidraw Portal
 
 Collaboration server for Excalidraw
+
+# Development
+
+- install
+
+  ```sh
+  yarn
+  ```
+
+- run development server
+
+  ```sh
+  yarn start:dev
+  ```
+
+# Deployment
+
+NOTE: currently the server IS NOT deployed automatically on push to the `master` branch, and must be done so manually by an admin.