add new document with asciidoctorj 1.5.0 release notes.
updates manual with new additions.
revisions to AsciidoctorJ 1.5.0 announcement
first round of edits to AsciidoctorJ manual

- rewrote intro
- switched off compat-mode
- changed naming convension for uri references
- updated artifact information
- added Bintray repository information
- removed references to the render* methods except for one admonition
- general revisions to content
Merge pull request #1 from mojavelinux/asciidoctorj-edits

revisions to AsciidoctorJ 1.5.0 announcement
Merge pull request #2 from mojavelinux/asciidoctorj-edits-2

first round of edits to AsciidoctorJ manual
Merge pull request #275 from lordofthejars/master

AsciidoctorJ 1.5.0 manual and release announcement