Fix Facebook link

also in threads templates

Change-Id: Ieac5d0f49a9da25392e26518df33908a5f0b7087
Add guide to prepare construction

* PS1 - Add guide
* PS2 - More detailed instructions for configuring ccache
* PS3 - Remove remove whitespace

Change-Id: Icccb898ee7bdfbbeb523fe4d5553b723ccb8f94a
Merge "Add guide to prepare construction" into pac-4.4
Merge remote-tracking branch 'pac/pac-4.4' into pac-4.4