[doc][docs infra] update instructions for installing lint dependencies

[angelinalg]

Description

Got dependency conflicts after installing lint requirements, while trying to set up local docs build environment.

Link

https://docs.ray.io/en/master/ray-contribute/docs.html#install-dependencies

[evalaiyc98]

I think the problems are interrelated. When I followed the guide, I think there are no dependency conflicts in lint-requirements.txt. The screenshot below displays the result of running pip install -r python/requirements/lint-requirements.txt.

However, there were indeed dependency conflicts in text-requirements.txt, as illustrated in the screenshot below.
Result of running pip install -c python/requirements.txt -r python/requirements/test-requirements.txt

[evalaiyc98]

@peytondmurray Are you interested in resolving this? If not, I'd be more than happy to contribute.

[peytondmurray]

@evalaiyc98 If you're happy to do it, I'm happy to let you! Thanks so much!

[anyscalesam]

@evalaiyc98 any ETA on that PR?

[evalaiyc98]

I think I will try my best in two weeks, if not achieve the goal, I will close that PR.

[aslonnie]

not sure if this is still relevant.