Increase the depth of some ToCs to 2 for easier navigation (backport #6168)

[mergify]

Description

This is a minor user experience improvement.

I was reading the intra-process tutorial and saw that the table of contents isn't very useful:

In most cases, increasing the depth from 1 to 2 doesn't really "cost" anything and is pretty helpful IMO. Therefore, I looked for pages that aren't too short, have more than 1 level of sections, and use a ToC with a depth of 1, and increased their depth to 2.

Did you use Generative AI?

Additional Information

There's no reason not to try backporting this.

---

This is an automatic backport of pull request #6168 done by Mergify.

[mergify]

Cherry-pick of 6eacc23 has failed:

On branch mergify/bp/jazzy/pr-6168
Your branch is up to date with 'origin/jazzy'.

You are currently cherry-picking commit 6eacc23.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   source/How-To-Guides/Configure-ZeroCopy-loaned-messages.rst
	modified:   source/How-To-Guides/Installation-Troubleshooting.rst
	modified:   source/How-To-Guides/Launch-file-different-formats.rst
	modified:   source/How-To-Guides/Node-arguments.rst
	modified:   source/Tutorials/Demos/Intra-Process-Communication.rst

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   source/Tutorials/Demos/Action-Introspection.rst

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[christophebedard]

We should just delete source/Tutorials/Demos/Action-Introspection.rst here.

[fujitatomoya]

action introspection is not available, so we need to remove that file.

[github-actions]

HTML artifacts: https://github.com/ros2/ros2_documentation/actions/runs/21192931919/artifacts/5197980810.

To view the resulting site:

1. Click on the above link to download the artifacts archive
2. Extract it
3. Open html-artifacts-6174/index.html in your favorite browser