Missing build step on "next steps"

[Giuliano1993]

When starting a project, in the list of suggest next steps we've got:

5. Click the Load unpacked extension button.
6. Select the build/ directory that was created.

putting a step in the middle telling to run npm run build would make things clearer for devs who are less into JS processes!
I can open a PR for this If you want

[mrienstra]

docs(i18n):Deutsch changes to index.ts added some redundancy to the instructions, and maybe a bit too much indentation as well.

Sample, when using pnpm:

Done. Now run:

  cd my-crx-app
  pnpm install
  pnpm run dev

   Suggest you next step:
    1. cd my-crx-app
    2. Run pnpm install
    3. Open chrome://extensions/ in your browser
    4. Check the box for Developer mode in the top right.
    5. Click the Load unpacked extension button.
    6. Select the build/ directory that was created.

Could change to something more like:

Done. Now run:

cd my-crx-app
pnpm install
pnpm run dev

To load the extension:

1. Open chrome://extensions in your browser.
2. Enable Developer Mode by clicking the toggle switch next to Developer mode (top right).
3. Click the Load unpacked button and select the build/ directory.

See index.ts#L375-L397 for current source.