Kurt collins 297bedbfc7 Editing intro.md for style and grammar (#1630)
Updated some formatting and style for readability.

**Summary**

Looking through the docs and found some language that didn't read clearly or was formatted strangely. I decided to update the file for readability.

**Test plan**

**A picture of a cute animal (not mandatory but encouraged)**
![image](https://user-images.githubusercontent.com/42543284/44350791-38235e80-a46e-11e8-8bf5-6fd96d2bf598.png)
2018-08-20 14:32:52 -04:00
..
2018-08-20 14:09:24 -04:00