Update the README

[timpokorny]

Summary

The README file shipped with PGauge is empty and the one in the repository isn't much use. Update them both so that they describe the major components of the application and how to configure and use it for your RTI.

Acceptance Criteria

• README file shipped with PGauge contains useful information on the major components of the application and instructions on how to configure and use
• README in the root of the repo is updated to include some useful documentation on the project and how to get started with the source

[yogeshVU]

How do one use this tool? Readme with the instruction set will be very useful