Refine documentation

1 job for esm in 1 minute and 45 seconds (queued for 2 seconds)
Status Job ID Name Coverage
failed #257


Name Stage Failure
build_image Test
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the pagedjs@0.1.31 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /home/node/.npm/_logs/2019-03-23T22_10_56_294Z-debug.log
npm ERR! Test failed. See above for more details.
ERROR: Job failed: exit status 1