cleans up the preface page

replaced hard links with soft pointing to the correct pages

Change-Id: I743e477a3b9a7648795c0c7dd52bd47c42a51527
Closes-Bug: #1254541
restructure operator training guide

fixed up operator getting started lab

implements blueprint training-manuals

Change-Id: I5728be6704131a67ceb8b7e00abe76b27224ee65
restructure operator training guide

added updated object storage node material. nermina is waiting on including this.

implements blueprint training-manuals

Change-Id: Ia46a289fd6043de6dee1dbc5666acba144af5656