Add misc page for temporarily linking to older wiki pages

This page mainly serves as a jump-in point for the pages of an earlier
version of these documents previously in form of a GitLab wiki.
The ultimate goal/plan for the following pages is to rewrite and/or
reorganize them into the three manuals of Jami: the user manual, the
build manual, and the developer manual.  Thus, the pages linked to
from this page may be moved at any given time.

Change-Id: Iaa4c6ca8cc676a76daa6c3cb30d7772b5ed1a5fc