[Readme] update repository and bump vLLM to 0.8.0

[yannicks1]

Readme: update repository and bump vLLM to 0.8.0

changes:

• point to repository on vllm-project (commit) (thanks @nikolaospapandreou for spotting this!)
• bump version from 0.7.3 to 0.8.0 (commit)

Note: only merge after PR #37 has been merged.

[github-actions]

👋 Hi! Thank you for contributing to vLLM support on Spyre.
Just a reminder: Make sure that your code passes all the linting checks, otherwise your PR won't be able to be merged. To do so, first install the linting requirements, then run format.sh and commit the changes:

pip install -r requirements-lint.txt
bash format.sh

Now you are good to go 🚀

[joerunde]

lgtm!