Update Debian installation instructions

[sarakonradi]

This PR updates the installation instructions for Debian. It also creates separate Ubuntu and Debian tabs for added clarity.

It fixes #1349.

[sarakonradi]

@steffengraber Thanks for your suggestions! I added the changes.

[steffengraber]

Perfect!

[terhorstd]

Indentation causes the file to not render well on Github, while all other pages do. They render fine with sphinx though.

https://github.com/nest/nest-simulator/blob/3e23c1f201a1bd9ffe357b01c166fd8779aa4191/doc/installation/index.rst

[sarakonradi]

Indentation causes the file to not render well on Github, while all other pages do. They render fine with sphinx though.

https://github.com/nest/nest-simulator/blob/3e23c1f201a1bd9ffe357b01c166fd8779aa4191/doc/installation/index.rst

@terhorstd Yes, I noticed that too. The indentation is needed for the tabs to render with Sphinx and on RtD.

Our options are:

1. We keep the tabs, since they work fine on RtD.
2. We remove them and create separate files for the different operating systems.

What do you think?

[clinssen]

Hi, I've run into similar issues before. Support for rendering Markdown or reStructuredText on GitHub is very restricted. This is by design (due to security implications) and is fair enough from GitHub's perspective, but I would recommend against designing files such that they render well on github.com. We should nevertheless aim for something that is as standards-compliant as rST/MD gets (pandoc support seems a good target and also implies good readthedocs compliance).

For the particular case of tabs in the UI, I don't have any strongly held opinions about keeping them or removing them.

[terhorstd]

I agree with @clinssen, that we should not explicitly design files for github. The indentation is apparently required for ..tabs: to work.

Generally keeping or removing tabs and discussing adequate use-cases should be split from this PR.

[terhorstd]

With the additional packages installed, it works for me on Debian 11. Nice!
These packages should then also be mentioned in the instructions.

I also added some suggestions to point the user to the right places to look for "NUMBER", etc.. I didn't check the formatting of those suggestions though, so if you accept them, please also verify they render well.

One warning could be mentioned, or taken care of in another PR. Only fix it here if it's clear and easy to fix.

[terhorstd]

LGTM! 👍