Update README

Author: adampetro

README.md

@@ -1,12 +1,36 @@
 # Function Examples
 
-This is the home of all the public examples of Shopify Functions. It's used by the CLI when running `yarn shopify app scaffold extension`. Feel free to look around! Do not edit these files directly.
+This is the home of all the public examples of Shopify Functions. It's used by the CLI when running `yarn shopify app generate extension`. Feel free to look around! Do not edit these files directly.
 
 ## Local Development
 
+### Expand Liquid Templates
+
 If you wish to run the samples directly from this repository, you must first expand any `.liquid` templates with the following command.
 
 ```shell
 yarn
-yarn expand-liquid 
-```
+yarn expand-liquid
+# optionally provide the language flavor
+yarn expand-liquid vanilla-js
+yarn expand-liquid typescript
+```
+
+### Run Tests
+
+```shell
+# JavaScript
+yarn test-js
+# TypeScript
+yarn test-ts
+# Rust
+cargo test
+```
+
+### Lint
+
+```shell
+# currently only applies to Rust
+cargo fmt
+cargo clippy -- -D warnings
+```