Update installation instructions

[jemrobinson]

:white_check_mark: Checklist

• [x] You have given your pull request a meaningful title (e.g. Enable foobar integration rather than 515 foobar).
• [x] You are targeting the appropriate branch. If you're not certain which one this is, it should be develop.
• [x] Your branch is up-to-date with the target branch (it probably was when you started, but it may have changed since then).

:vertical_traffic_light: Depends on

• 2154

:arrow_heading_up: Summary

• Update instructions to install with pipx
• Could also upload to PyPI to simplify further

:closed_umbrella: Related issues

Closes #2084

:microscope: Tests

Installation

Usage

Package contents verification

/Users/jrobinson/.local/pipx/venvs/data-safe-haven/bin/dsh $ ls -alh /Users/jrobinson/.local/pipx/venvs/data-safe-haven/lib/python3.12/site-packages/data_safe_haven total 32 drwxr-xr-x@ 22 jrobinson staff 704B 22 Aug 17:38 . drwxr-xr-x@ 143 jrobinson staff 4.5K 22 Aug 17:38 .. -rw-r--r--@ 1 jrobinson staff 171B 22 Aug 17:38 __init__.py drwxr-xr-x@ 6 jrobinson staff 192B 22 Aug 17:38 __pycache__ drwxr-xr-x@ 5 jrobinson staff 160B 22 Aug 17:38 administration drwxr-xr-x@ 11 jrobinson staff 352B 22 Aug 17:38 commands drwxr-xr-x@ 11 jrobinson staff 352B 22 Aug 17:38 config drwxr-xr-x@ 7 jrobinson staff 224B 22 Aug 17:38 console -rw-r--r--@ 1 jrobinson staff 684B 22 Aug 17:38 directories.py drwxr-xr-x@ 4 jrobinson staff 128B 22 Aug 17:38 exceptions drwxr-xr-x@ 6 jrobinson staff 192B 22 Aug 17:38 external drwxr-xr-x@ 6 jrobinson staff 192B 22 Aug 17:38 functions drwxr-xr-x@ 8 jrobinson staff 256B 22 Aug 17:38 infrastructure drwxr-xr-x@ 7 jrobinson staff 224B 22 Aug 17:38 logging drwxr-xr-x@ 5 jrobinson staff 160B 22 Aug 17:38 provisioning drwxr-xr-x@ 11 jrobinson staff 352B 22 Aug 17:38 resources drwxr-xr-x@ 7 jrobinson staff 224B 22 Aug 17:38 serialisers -rw-r--r--@ 1 jrobinson staff 496B 22 Aug 17:38 singleton.py drwxr-xr-x@ 7 jrobinson staff 224B 22 Aug 17:38 types drwxr-xr-x@ 5 jrobinson staff 160B 22 Aug 17:38 utility drwxr-xr-x@ 6 jrobinson staff 192B 22 Aug 17:38 validators -rw-r--r--@ 1 jrobinson staff 71B 22 Aug 17:38 version.py ```

Dependency versions

[github-actions[bot]]

Coverage report

This PR does not seem to contain any modification to coverable code.

[jemrobinson]

Is it worth also mentioning that you could install to a venv? (Anyone who wants to do that probably already knows).

Yes, I'll add that too.