Add ignore file
Add code to retrieve and unzip source data
Add blank of main script
Add code through extracting only mean and std
Consolidate code in run_analysis.R file

Retrieval action is no longer separate.
The run_analysis.R file will check for the
source data existing or the zip file existing
and take the necessary actions so that the source
data resides in path "UCI HAR Dataset/"
DOC: Add function comments
Add better script feedback
Add call to prepare function
Complete steps 1, 2, 4 and restructure code

Code is restructured to group comment code as
completing the steps required in the project
Add rhistory to ignore file
Improved feedback message formatting
Complete run_analysis.R