Add usage information for async rendering

[Dreamsorcerer]

No description provided.

[codecov]

Codecov Report

Merging #396 (cf4c846) into master (0576d2c) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #396   +/-   ##
=======================================
  Coverage   96.25%   96.25%           
=======================================
  Files           3        3           
  Lines         160      160           
  Branches       18       18           
=======================================
  Hits          154      154           
  Misses          6        6           

Flag	Coverage Δ
unit	95.62% <ø> (ø)

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