[1.3][DOCS] Fixes SIEM links#927

Merged

webmat merged 2 commits intoelastic:1.3from

webmat:backport_908_1.3

Aug 18, 2020

Commits on Aug 13, 2020

Adjust SIEM link for app rename, use shortcut for logs UI link
Mathieu Martin
committed

Commits on Aug 17, 2020

Final pass at link text:
Mathieu Martin
committed