Implement Jazzband guidelines for django-postgres-utils

This issue tracks the implementation of the [Jazzband guidelines](https://jazzband.co/about/guidelines) for the project [django-postgres-utils](https://github.com/jazzband/django-postgres-utils)

It was initiated by @crazyscientist who was automatically assigned in addition to the [Jazzband roadies](https://jazzband.co/roadies).

See the [TODO list](#todos) below for the generally required tasks, but feel free to update it in case the project requires it.

Feel free to ping a [Jazzband roadie](https://jazzband.co/roadies) if you have any question.

## TODOs

- [x] Fix all links in the docs (and README file etc) from old to new repo
- [x] Add the [Jazzband badge](https://jazzband.co/about/guidelines#badges) to the `README` file
- [x] Add the [Jazzband contributing guideline](https://jazzband.co/about/guidelines#contributing-guidelines) to the `CONTRIBUTING.md` or `CONTRIBUTING.rst` file
- [x] Check if continuous testing works with [GitHub Actions](https://github.com/features/actions)
- [ ] Check if test coverage is tracked with [Codecov](https://codecov.io)
- [x] Add `jazzband` account to [PyPI](https://pypi.org/) project as maintainer role (e.g. URL: https://pypi.org/manage/project/django-postgres-utils/collaboration/)
- [x] Add `jazzband-bot` as maintainer to the [Read the Docs](https://readthedocs.org/) project (e.g. URL: https://readthedocs.org/dashboard/django-postgres-utils/users/)
- [ ] Add incoming GitHub webhook integration to Read the Docs project (e.g. URL: https://readthedocs.org/dashboard/django-postgres-utils/integrations/)
- [x] Fix project URL in [GitHub project](https://github.com/jazzband/django-postgres-utils) description
- [x] Review project if other services are used and port them to Jazzband
- [ ] Decide who is project lead for the project (if at all)
- [ ] Set up CI for Jazzband project releases if needed and open ticket if yes

## Project details

Description
Django app providing additional lookups and functions for PostgreSQL


Homepage
None


Stargazers
1


Open issues
0


Forks
3


Default branch
master


Is a fork
False


Has Wiki
True


Has Pages
False