feat(nvim): add "**" again
feat(nvim): add "**" again

As noted, not quite the same as what I had with UltiSnips, but it
delivers 90% of the value.

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