Update README.md
Add license file and remove old readme
GrizzlyDriver: Initial commit with basic code
GrizzlyDriver: Initial port of features from PiER drivers
GrizzlyDriver: Disable command timeout in USB mode
GrizzlyDriver: Initial xbox controller interface skeleton. Write commands seem to work
GrizzlyDriver: Documented usb library. Other misc changes
GrizzlyDriver: Remove ipython notebook
GrizzlyDriver: Make default example use position control. Add a readme for troubleshooting etc
GrizzlyDriver: Fix a few misc oversights

1. Switched whitespace from tabs to spaces
2. Renamed functions to use under_score naming
3. Fix 4 byte reads to be interpreted as signed integers
4. Ignore *.ipynb files
5. Updated the example code to use more features
GrizzlyDriver: Improve error checking and interface

1. Provide udev rule so that users can choose not to run code as root.
2. Make sure that inputs as acceleration limit and current limit are reasonable.
3. Remove the need for creating a GrizzlyUSB object. Example code updated to reflect this.
4. Add functionality with specific changes in firmware to support multiple device addressing. Still only supports the maximum number of i2c addresses available on the device.
5. Throw more intuitive errors instead of AssertionErrors.
Added new xbox controller udev rule so that it does not require sudo.