Add --update arg to init-launch-sandbox (#1760)

## Checklist

- [ ] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [ ] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [ ] I have not broken the cheatsheet

Author: pokey

docs/contributing/CONTRIBUTING.md

@@ -37,7 +37,7 @@ extension](#running--testing-extension-locally). You may also find the [VSCode A
    pnpm init-vscode-sandbox
    ```
 
-   The `pnpm init-vscode-sandbox` command creates a local [VSCode settings profile](https://code.visualstudio.com/updates/v1_72#_settings-profiles) that acts as a sandbox containing a specific set of VSCode extensions that will be run alongside Cursorless when you launch Cursorless in debug or test mode. This approach is [suggested](https://code.visualstudio.com/updates/v1_72#_extension-debugging-in-a-clean-environment) by the VSCode documentation. If you'd like to use additional extensions when debugging locally, you can use the following command:
+   The `pnpm init-vscode-sandbox` command creates a local [VSCode settings profile](https://code.visualstudio.com/updates/v1_72#_settings-profiles) that acts as a sandbox containing a specific set of VSCode extensions that will be run alongside Cursorless when you launch Cursorless in debug or test mode. This approach is [suggested](https://code.visualstudio.com/updates/v1_72#_extension-debugging-in-a-clean-environment) by the VSCode documentation. If you need to update any of the extension dependencies in the sandbox, you can add `--force` to the command. If you'd like to use additional extensions when debugging locally, you can use the following command:
 
    ```bash
    code --profile=cursorlessDevelopment --install-extension some.extension

packages/cursorless-vscode/src/scripts/initLaunchSandbox.ts

@@ -17,12 +17,19 @@ async function main() {
       ),
     ];
 
+    if (process.argv.includes("--force")) {
+      args.push("--force");
+    }
+
     // Install extension dependencies
-    const process = cp.spawn("code", args, { stdio: "inherit", shell: true });
+    const subprocess = cp.spawn("code", args, {
+      stdio: "inherit",
+      shell: true,
+    });
 
     await new Promise<void>((resolve, reject) => {
-      process.on("error", reject);
-      process.on("exit", (code) => {
+      subprocess.on("error", reject);
+      subprocess.on("exit", (code) => {
         if (code === 0) {
           resolve();
         } else {