Added echoing VR positions

This release adds an echo to the websocket that replies with the positions of the attached VR devices. No idea how accurate it is.

To use either follow the build and install instructions in the README, or:

• Download and extract driver.zip
• Navigate to C:\Program Files (x86)\Steam\steamapps\common\SteamVR\drivers
• Paste the contents of driver.zip into this folder