Prep for version 3.8

[tim-schilling]

Added a 3.8 section to the changes documentation.

Description

Related Issue

This resolves #1443.

#1441 should be merged in before this.

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have run the pre-commit run command to format and lint.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have added my name and/or github handle to AUTHORS.rst
• I have added my change to CHANGES.rst
• All new and existing tests passed.

[ddabble]

@treyhunner Could you release version 3.8.0 to PyPI? 🙂 (This will hopefully be the last time we need to ask you for this, considering the planned transfer to Django Commons 😅)

[treyhunner]

@treyhunner Could you release version 3.8.0 to PyPI? 🙂 (This will hopefully be the last time we need to ask you for this, considering the planned transfer to Django Commons 😅)

Released 👍