As per discussion in the OSA docs summit session, clean up of installation guide. This fixes typos, minor RST mark up changes, and passive voice. This patch also merges a some of the sections into the larger chapter. This is in an effort to remove multiple smaller files. This patch is the first of many to avoid major conflicts. Change-Id: I5b6d540bfa691b36dbe9cf909de8e61affb0cd92