Fix README rendering on PyPI

[pllim]

Project Description rendering is broken on the PyPI page, making it hard to read.

https://pypi.org/project/autogalaxy/

Screenshot of the beginning...

astropy/astropy.github.com#491 (comment)

[Jammy2211]

This is now fixed, albeit it'll be a few days until its done on pypi as we need to do a release.

The test pypi shows we have fixed the source code - https://test.pypi.org/project/autogalaxy/