[PATCH] Minor typos corrected in docs

I was reading various documents in the llvm/docs/ directory and found a few minor typos.

I don’t have write access so if someone could apply these for me, that would be great.

I can’t apply this diff. Can you send the patch as an attachment?

I already got it earlier, apologies for not replying to the list.

-eric

I already got it earlier, apologies for not replying to the list.

For those interested, this was r229884.

-- Sean Silva