Modernize

See merge request !4

Add an @private decorator

Closes #3

See merge request !5

* Update Windows CI job
* Move docs and tests into the top-level directory
* Update RTD configurations
* Add documentation for @private
* Intersphinx
* Clean up type checking

Cleanup files

Closes #7

See merge request !6

Add an index and don't pollute site-packages

See merge request !7

Rename tests/ to test/

Closes #8

See merge request !8

* Update copyright years.

Include ``test/__init__.py`` and ``docs/__init__.py`` (GL#9)

See merge request !9

I blue it!

See merge request !10

Closes #9

Add py.typed marker file

Closes #9

See merge request !11

Fix links to the guide and API reference in 'index.rst'

See merge request !12

public() can't be type annotated

Closes #10

See merge request !13

Do type hinting the right way

Closes #10

See merge request !14

Improve QA

See merge request !15

Convert to pyproject.toml and use PDM as the package manager

See merge request !16

Also, remove an unnecessary pdm setting.

Fix some typos

See merge request !18

Cleanups and consistencies

See merge request !19

Update terminology

See merge request !20

Fix some typos

See merge request !21

Fix pdm deprecation

See merge request !22

Update docs/NEWS.rst

See merge request !23

* Exclude certain local cache files from the sdist/wheel.
* Updates for pdm and dependencies.

Add support for Python 3.11

See merge request !24

Strengthen CI constraints

See merge request !25

Improvements to GitLab CI integration

See merge request !26

Testing the new GitLab CI script

See merge request !27