docs: update readme with local dev instructions (#43)

* docs: update readme with local dev instructions

* fix: lint

* docs: cleanup

README.md

@@ -125,6 +125,32 @@ This monorepo is comprised of the following packages, products, and examples:
    [workspace protocol](https://pnpm.io/workspaces#workspace-protocol-workspace)
    to link SDK in the new folder.
 
+3. Start a local node:
+
+   ```bash
+   npx zksync-cli dev start
+   ```
+
+4. Compile and deploy contracts to the local node:
+
+   ```bash
+   # Compile and deploy contracts
+   cd packages/contracts
+   pnpm build
+   pnpm run deploy
+   ```
+
+5. Start the demo application:
+
+   ```bash
+   # Go back to root folder to start demo app
+   cd ../..
+   pnpm nx dev demo-app
+   ```
+
+Your local Auth Server will be running at `http://localhost:3002/`, and the demo
+app will be running at `http://localhost:3004/`.
+
 ## Running commands
 
 Use the NX CLI to run project commands, however PNPM is still usable as an