Update README.md with compile instructions (#11)

README.md

@@ -1,6 +1,6 @@
 # Simple Account Abstraction Snap
 
-This repository contains a simple example of a keyring snap.
+This repository contains a simple example of an account abstraction keyring snap.
 
 Keyring snaps enable developers to enhance MetaMask by adding new account
 types. These accounts are natively supported within the extension, appearing in
@@ -23,7 +23,17 @@ template](https://github.com/MetaMask/template-snap-monorepo/generate) and
 setup the development environment:
 
 ```shell
-yarn install && yarn start
+yarn install
+```
+
+compile types
+```shell
+cd packages/snap && yarn compile
+```
+
+start the application (cd back into root of repository)
+```shell
+yarn start
 ```
 
 ## Cloning