docs(update readme): update installation guide

2 jobs from devel-windows in 2 minutes and 36 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Cleanup Build
skipped #1250
on_build_failure
 
  Build In Devel Windows
failed #1251
shell allowed to fail
build_in_devel_windows

02:36

 
Name Stage Failure
failed
build_in_devel_windows Build In Devel Windows
npm ERR! bcrypt@3.0.6 install: `node-pre-gyp install --fallback-to-build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the bcrypt@3.0.6 install 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! C:\Windows\system32\config\systemprofile\AppData\Roaming\npm-cache\_logs\2019-11-18T10_16_01_935Z-debug.log
ERROR: Job failed: exit status 1