Update train_autopilot.md

Update roll_your_own.md

Update setup_raspberry_pi.md

Update setup_raspberry_pi.md

Update images.

Update stores.md

Update about.md

Update simulator.md

Update setup_raspberry_pi.md

Fixed some typos in build_hardware.md

Add section to move model from host  back to the car, add more details about preparing car for automatic driving.

Add URLs to markku.ai project

Fixes #493

added link for finding WiFi configuration file "country" codes.

Replace hand drawn image with a render.
Use lowercase extensions for images.

Add URL to rosbags.

Fix typos.

* ensure docs guide how to handle SD card in a safe way
* make formatting more consistent
* ensure headers about optional steps are easier to spot
* add more details about setting up hostname and discovering IP of the device
* minor fixes

Update setup_mac.md

Update setup_ubuntu.md

Update setup_windows.md

Clarification on what hardware tensorflow-gpu operates

Clarification on when to install tensorflow-gpu

Clarification on when to install tensorflow-gpu

Travis update

Documentation: Editing myconfig.py without changing directory

The previous page of instructions could mostly be copied and pasted into terminal and would work. This small change allows that to continue for this line.

black - The uncompromising Python code formatter.
https://github.com/psf/black
It requires python 3.6 or newer, though