Add Readme.md file and file content

Reviewed MR!7, i have found one issue.
1. Two lines prior to ##/### headings

Good catch @Nupur Badola, I also fixed a few lines longer than 80 characters.

Getting some warning:

7.diff.txt:9: trailing whitespace.
Feeds Tamper provides a small plugin architecture for Feeds to modify data
7.diff.txt:10: trailing whitespace.
before it gets saved. Several plugins are available by default and are
warning: 2 lines add whitespace errors.