chore(nvim): clean up spell file
chore(nvim): clean up spell file

Some of these had capitalized and non-capitalized variants; we only need
the latter, because it covers both.

There was also one misspelled word in here ("reservior"), which I
removed.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent