Preliminary slides for the intro section.
Adds an images directory.
Adds YAML slides.
Removes empty slide.
REmoves composer from intro slides.
End ntroductory slides.
Initial slides for the Plugins session on day 1.
Merge branch 'master' into ken
Merge branch 'ken'
Formatting cleanup for Ken's slides.
Merge remote-tracking branch 'origin/ken'
Merge branch 'slides-robin'

Conflicts:
	index.html
Fixes Proxima Nova bold font calls.
Fixes Proxima Nova bold font calls.
Fixes semibold fonts.
Clean up plugins slides a bit, added some html comments to help us identify where things start and end.
Minor cleanup.
Add BinaryFileRepsonse example.
Minor cleanup.
Split opening chapter into 2 sections.