Centralized setting of chunk options for novice R materials.
Added back fig.path option to novice R lesson 01.
Make jekyll ignore Rmd files.
Added Makefile for converting R Markdown files to Markdown.
Added rmarkdown to list of .PHONY targets.
Changed rmarkdown to rmd.
Changed one last instance of rmarkdown to rmd.
Merge pull request #626 from jdblischak/display_w_hooks

Makefile for converting R Markdown files to Markdown