Fix a mixed up have_cli / have_workers in the pyproject jinja template.

Remove `usedevelop=true` options; these are not needed and can generate
a build error on some swh packages.

This is handled in swh-docs directly.

Make black and isort run before flake8 so that black can fix style
issues before flake check for these.

and add a test file to be able to run pytest.

These tox environments will create a test swh project from the template
and run the corresponding test from the generated project.

It's not very pretty, but...

This adds a tox file which simply runs the `copier copy` command; no
other validation is made so far.

See the README file.

It now needs types-click which is indeed a dependency of
swh.core[testing].

GitLab will display the content of the README file when browsing the
repository. But in case the file is a symlink, it will display the
path pointed by the symlink. There is a 6 year old issue about this:
https://gitlab.com/gitlab-org/gitlab/-/issues/15093

We can workaround the issue by having the content at the root of the
repository and a symlink to this file in the `docs/` directory.

Related to swh/meta#4960

Related to swh/meta#4959

`swh-foo` is used through the template as our example module name.
The documentation template used `swh-py-template` instead.
Let’s use `swh-foo` here as well so template users can look for
the string `foo` until they have customized everything.

- Switch from Phrabricator to GitLab.
- Update pre-commit dependencies.
- Update copyright years.

This fixes python 3.7 support due to poetry, a dependency of isort, that
removed support for that Python version in a recent release.

In order to remove warnings about /apidoc/*.rst files being included
multiple times in toc when building full swh documentation, prefer to
include module indices only when building standalone package documentation.

Related to T4496

- pre-commit from 4.1.0 to 4.3.0,
- codespell from 2.2.1 to 2.2.2,
- black from 22.3.0 to 22.10.0 and
- flake8 from 4.0.1 to 5.0.4. Also freeze flake8 dependencies.

Also change flake8's repo config to github (the gitlab mirror
being outdated).

That hook can be frustrating as it can discard a long commit message
if it finds a typo in it so better removing it.

Related to T3922

black is considered stable since release 22.1.0 and the version
we are currently using is quite outdated and not compatible with
click 8.1.0, so it is time to bump it to its latest stable release.

Please note that E501 pycodestyle warning related to line length
is replaced by B950 one from flake8-bugbear as recommended by black.
https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#line-length

Related to T3922

pytest-postgresql 3.1.3 and pytest-redis 2.4.0 added support for
pytest >= 7 so we can now drop the pytest pinning.

Due to test modules being copied in subdirectories of the
build directory by setuptools, it makes pytest fail by raising
ImportPathMismatchError exceptions when invoked from root
directory of the module.

So ignore the build folder to discover tests.

To install the new hook:

  $ pre-commit install -t commit-msg

Related to T3916

This also drops spurious copyright headers to those files if present.

Related to T3812

Visual Studio Code is getting popular nowadays and the
.vscode directory often gets included by mistake.
This commit will improve the developer experience.

Enable to check package documentation can be built without producing
sphinx warnings.

The sphinx environment is designed to be used in continuous integration
in order to prevent breaking documentation build when committing changes.

The sphinx-dev environment is designed to be used inside a full swh
development environment.

Related to T3258

* Swap docs/README.rst and README.rst
* move index.rst's content to README.rst
* Also fix the mimetype in setup.py