Add a note about plugin specific settings #36

Job	Run time
lint	5s
docs / test	1m 0s
base-images	20m 48s
app-images (nightly, pulp-minimal)	2m 0s
app-images (nightly, pulp)	1m 59s
app-images (nightly, galaxy-minimal)	1m 59s
app-images (nightly, galaxy)	1m 57s
app-images (stable, pulp-minimal)	1m 57s
app-images (stable, pulp)	1m 59s
app-images (stable, galaxy-minimal)	1m 58s
app-images (stable, galaxy)	1m 58s
	37m 40s

Provide feedback