docs: Add document for vhost-user

[carezkh]

[codecov[bot]]

Codecov Report

Merging #87 (0891003) into main (4f6ab5e) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #87   +/-   ##
=======================================
  Coverage   34.11%   34.11%           
=======================================
  Files           6        6           
  Lines        1952     1952           
=======================================
  Hits          666      666           
  Misses       1182     1182           
  Partials      104      104           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.