WIP: add Reveal.js project as "talks" folder.

From hakimel/reveal.js@f51067b00e8099bb576858e70db6e2fc44ce3d61:

https://github.com/hakimel/reveal.js/
WIP: stub out QCon SF talk and add redirect.
QCon SF talk: stub out specific configs, etc.
QCon SF talk: add support for speaker notes.
QCon SF 2012: WIP talk.
QCon SF talk: finish; now general Neo4j talk.
Neo4j talk: rename talk and images directory.
Neo4j talk: polish up speaker notes for sharing.
Neo4j talk: rename (again) to Neo4j.
Merge branch 'feature/neo4j-talk' into develop
Merge branch 'develop' into gh-pages