docs: Added badges to README.md

[max-pfeiffer]

I added the following badges:

• Poetry
• Ruff
• Supported Python versions
• Workflow runs

[alexanderankin]

here are the ones on readthedocs (which still needs to be fixed on the build side (either transferring the testcontainers-python subdomain, or the testcontainers subdomain set up via someone's auth who has permissions to create webhooks on this repo):

testcontainers-python/index.rst

Lines 1 to 11 in d5b8553

	testcontainers-python
	=====================
	.. image:: https://github.com/testcontainers/testcontainers-python/actions/workflows/ci-core.yml/badge.svg
	:target:https://github.com/testcontainers/testcontainers-python/actions/workflows/ci-core.yml
	.. image:: https://img.shields.io/pypi/v/testcontainers.svg
	:target:https://pypi.python.org/pypi/testcontainers
	.. image:: https://readthedocs.org/projects/testcontainers-python/badge/?version=latest
	:target:http://testcontainers-python.readthedocs.io/en/latest/?badge=latest
	.. image:: https://github.com/codespaces/badge.svg
	:target:https://codespaces.new/testcontainers/testcontainers-python

[alexanderankin]

maybe it makes sense for the badges to match, maybe not, idk

[max-pfeiffer]

@alexanderankin Thanks for pointing that out. I just added the missing badges for docs and codespace. I choose to add the code space badge below the others is this one is breaking the layout a bit. That way it doesn't look too awkward.

@totallyzen The badges do match now. I just added some additional badges.

[alexanderankin]

im going to merge to test the webhook

[alexanderankin]

sorry, i thought this was merging into main, my apologies.