[Docs] Clean up moe_kernel_features.md

[windsonsea]

Perform a few improvement actions:

• fix typos and grammars
• remove redundant spaces from big markdown tables
• add newline chars to long paras

[mergify]

Documentation preview: https://vllm--28530.org.readthedocs.build/en/28530/

[gemini-code-assist]

Code Review

This pull request does a good job of cleaning up the moe_kernel_features.md document by fixing typos, grammar, and formatting. The changes improve the readability of the document. However, I've noticed a couple of areas in the tables that remain confusing due to duplicated or unclear entries. I've left specific comments with suggestions to address these to further improve the clarity of this important documentation.

[hmellor]

A nice change overall but a couple of general comments:

• I don't think the commas after e.g./i.e. are necessary
• The ' after experts are not necessary either. They are kernels for multiple experts, not kernels belonging to multiple experts

[hmellor]

For documentation we have been sticking to one line per paragraph because it's easier to maintain when editing the docs.

i.e. it's quite tedious to re-shuffle all the lines if you make an edit that makes one line in a multiline paragraph a bit longer