Clarify contributing tutorial and add Windows command examples

[Vandna]

The "Writing your first contribution" tutorial (docs/intro/contributing.txt) has some unclear wording in places, and several sections only show macOS/Linux commands (e.g. venv creation, running the test suite) without Windows equivalents. This ticket proposes clarifying the prose and adding the missing Windows commands alongside the existing ones, consistent with the pattern already used elsewhere in the doc.

[VIZZARD-X]

Hello Vandna, the docs have proven to be well structured and don't appear to be muddled. It would be useful to include/highlight the passage that feels unclear in your ticket to give contributors a better understanding. As far as commands are concerned, a toggle between macOS/Linux and Windows has been provided for most of the commands. To activate the venv as documented in the tutorial, Windows users should use:

%HOMEPATH%\.virtualenvs\djangodev\Scripts\activate.bat

[Jonathan Biemond]

Thanks Vandna, there is plenty of room for improving the wording. Regarding missing commands for on Windows, I didn't notice any, so just do a double check on your end. If you are working on a PR, please set yourself as the owner.

There's been some discussion on the forum around this page and others that might be really helpful.
​https://forum.djangoproject.com/t/public-notes-on-first-contribution-instructions-maybe-ideas-for-some-new-contributor-opportunities/45374

I've even written up some changes myself. Please use as much or as little from there as you like.
​https://github.com/django/django/compare/main...jonbiemond:django:docs/writing-your-first-contribution

[Vandna]

​PR

[Vandna]

Removed the duplicate Windows admonitions and fixed the line-length lint

error per review feedback.