Merge branch 'contribute' into 'master'

Add more details to CONTRIBUTE.md

See merge request !18
3 jobs for master in 1 minute and 1 second (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #25598
test

00:00:30

 
  Deploy
passed #25599
pages

00:00:31

passed pages:deploy

00:00:01