Repo Re-Org, More like ROS Package

- Reorganize repo so docker stuff is
  a folder within fast_rrt_ros ROS package
- Update filepaths in README
- Update `build_and_run_docker.bash`
  to use main folder as build context,
  but use Dockerfile inside docker folder
- Update filepaths in Dockerfile

scripts/3_default.bash

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+source /opt/ros/$ROS_DISTRO/setup.bash && \
+rm -rf build/ devel/ && \
+catkin_make -DCMAKE_BUILD_TYPE=Release && \
+source devel/setup.bash && \
+roslaunch husky_navigation move_base_mapless_demo.launch