[Docs] Acknowledge the files created as side effects after running commands

[VladimirFokow]

Summary of changes

Preview

Partially solves #4198 - describes this behavior in the docs

• is helpful for newcomers: acknowledges these files - now their creation is not a surprise
• and a quick suggestion what to do with these auto-generated files (add to .gitignore)

[abravalheri]

Hi @VladimirFokow, thank you very much for working on this.

Since we are talking about the quickstart page (and not a page that describes in depth the build process), I think it would be good to summarise the proposed content.

How about something along the lines:

.. note::
   During the build process - which is also triggered when you install the project from source code,
   e.g. ``pip install -e .`` - some directories hosting build artefacts and cache files may be
   created, such as ``build``, ``dist``, ``*.egg-info`` [#cache]_.
   You can configure your version control system to ignore them
   (see `GitHub's .gitignore template <https://github.com/github/gitignore/blob/main/Python.gitignore>`_
   for an example).

?

Then probably I would add a footnote saying something like:

.. [#cache]
   If you feel that caching is causing problems to your build specially after changes in the
   configuration files, consider removing ``build``, ``dist``, ``*.egg-info`` before
   rebuilding or installing your project.

[VladimirFokow]

Implemented this.
(& corrected a typo in the previous section: "file in file in your repository")

Now the pip install -e . command confusingly wraps onto the next line on my screen (the dot is on the next line).

I suggest:

.. note::

    During the build process from source code (for example, by ``pip install -e .`` or ``python -m build``)
    some directories hosting ...

[abravalheri]

Thank you, the suggestion looks good.

[abravalheri]

Thank you very much!