Edits to make novice R lesson 01 more similar to novice Python lesson 01.
Typo fixes.
Added some extra explanation on function calls.
Removed closed parentheses when referring to functions in the text.
read.table -> read.csv in novice R lesson 01.
parameter -> argument in novice R lesson 01.
In novice R lesson 01, created new object to store matrix instead of converting data frame. Also removed heatmaps, which can be introduced later.
Load first 5 lines of csv file so that it is always in sync with the data file.
Added more explanation of MARGIN argument to apply.
Removed mention of matrix by performing mathematical operations on the columns.
Merge pull request #639 from jdblischak/01-starting-with-data

Edits to make novice R lesson 01 more similar to novice Python lesson 01.