started data.table demo
updated data.table demo, added .md file
Added comments and extra explanation to examples.  Also added .R file with just code
removed generated files
Moved Rmd file to new directory in intermediate/misc/data.table
Fixed some typos, added example of larger file for fread() example
Fixed a typo (oops)
changes to data.table lesson, replaced system.time with microbenchmark, added table
delete generated files, fixed a small typo
updated README
Merge pull request #204 from sckott/master

Short introduction to the data.table library in R