[Effen] Add a README.txt file that describes how to test Effen using the stock app. Also includes a link to all the know bugs that affect the stock app.
[Effen] Add a README.txt file that describes how to test Effen using the stock app.
Also includes a link to all the know bugs that affect the stock app.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1145523003

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