Disable python 3.9 tests once more

Update docker inspect command in bug_report template

Fix typo in PR template

Fix build status badge

Ask for a release note entry

Fix typo in pull request template

Check that `develop` is target in PR ...

This is an update to the PR template.
It mostly adds text and some checks related to how good the template
is filled in and whether the `develop` branch was selected as base.

Fix failing GH Action

Enable tests with Python 3.9

Netbox is not yet compatible with Python 3.9

Building the Docker image with Github Actions

N/A when there's no issue

Pull request template suggestion

Adds more labels to the Dockerfile ...

It also updates the README and the bug_report template to reflect
the changes. Additionally, in the README some relevant shields from
shields.io are added.

The labels follow [label-schema.org][lsorg] and the [OpenContainer
image spec, section annotations][ocis], specifications.

[lsorg]: http://label-schema.org/rc1/
[ocis]: https://github.com/opencontainers/image-spec/blob/master/annotations.md

A new issue category for feature/change requests

Delete issue_template.md

Update issue templates

Update references to netboxcommunity

Mention the #netbox-docker Slack channel

✏️ Added an issue_template ...

With which I hope that people provide some basic information about
their project right away instead only on request.