First draft of the introduction

Rewrote the introduction as a usecase.

Pulled the introduction into a separate file.

This is a first draft but thought I'd get out a general idea of the introduction I had out as soon as possible.
"Many features of smartphones, such as the ease of sharing data, digital assistants, and many more, let users allow access to private data on their phone."
or:
"Smartphones are built around our social needs, and therefore make sharing of private data very easy for their users."