Expand cli documentation relating to the no-input flag (#1543)

[jeremyswerdlow]

Addresses the concerns in #1543 that not all side effects are clearly documented

[glumia]

Hey @jeremyswerdlow thanks for taking time for this, and sorry for the delay on the review!

While we're at it, I'd like to be able to fix other problems with flag's documentation within the codebase.

I tracked down all the places where no_input appears, and this is what I noticed:

• cookiecutter/main.py::cookiecutter
• cookiecutter/prompt.py::prompt_for_config
• cookiecutter/prompt.py::prompt_choice_for_config
• cookiecutter/repository.py::determine_repo_dir

In all those places the docstring just says "Prompt the user at command line for
manual configuration?". But as a user of this function, I ask myself: what
happens if the end-user isn't prompted for manual configuration? (I
should be able to understand it by looking only at the docstring)

• cookiecutter/zipfile.py::unzip

"Suppress any prompts" doesn't say anything about how the function
behaves in this case. Take a look at cookiecutter/utils.py::prompt_and_delete,
this is an example of good documentation: if I read the docstring I
don't have to guess what happens.

• cookiecutter/vcs.py::clone

Same as above, how does the function behave if the flag is True? (there's no mention
about the cache being refreshed).

• docs/advanced/suppressing_prompts.rst:6

We should document also here the fact that no_input causes a refresh of the cached resources.
I would also add a comment on line 6 to say that no_input corresponds to --no-input flag on the CLI.

Would you mind taking care of them?

[glumia]

Hey @jeremyswerdlow are you still interested on working on this?

I don't want to put pressure, it's just to know if I should wait or add those changes by myself and merge the pr.

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Update (2021-10-26)
Added the missing bits and assigned the review to someone else as this pull request now contains code submitted by myself.

[insspb]

@jeremyswerdlow @glumia Thank you for contribution, will be in next release.