Change file extension from rmd -> Rmd.
Set eval=FALSE for code chunk with hypothetical setwd statement.

Also change some of the output in md file because of system differences,
e.g. the number of decimal places to display.
Embed spreadsheet images.
Remove .Rhistory file.
Add link to supplemental lesson on read.csv from first R lesson.
Merge pull request #1 from jdblischak/csv_updates

Some edits to lesson on read.csv