update doc

tools/vscode/README.md

@@ -4,14 +4,30 @@ VS Code extension with language support for flux rust intermediate representatio
 
 ## Install
 
-To get the extension running you need to **build** the `vsix` file and **install** it manually
+**Step 1.** To get the extension running you need to **build** the `vsix` file and **install** it manually
 
 ```bash
 $ npm install -g typescript
 $ npm install -g vsce
 $ vsce package
 ```
 
+**Step 2.** Install `flux`
+
+Following [these instructions](https://flux-rs.github.io/flux/guide/install.html)
+
+**Step 3.** Configure `flux` in your workspace
+
+Ensure you have the following in your `flux.toml` for the workspace you want to use the extension in:
+
+```toml
+dump_checker_trace = true
+check_diff = true
+cache = true
+```
+
+**Step 4.** Run the extension!
+
 You can then **enable** the extension by runnning the `Toggle Flux View` command in the command palette.
 
 ## Features