Part-1 of improved RST docs for VCS

[aashish24]

• This is the part-1 of VCS documentation
• Updated to latest version of vcs
• Added new examples and text on conda install

Feedback and suggestions are welcome. Part-2 will be "Deep dive in VCS" explaining plots in detail.

[aashish24]

You can visit ReadTheDocs for VCS here: http://uvcdat.readthedocs.io/en/rst_docs/user-guide.html

[aashish24]

@doutriaux1 @danlipsa please review.

[doutriaux1]

This is an awesome start! Thanks @aashish24

[danlipsa]

@aashish24 Are these errors from your branch?
CMake Error at /usr/local/share/cmake-3.5/Modules/CPack.cmake:423 (message):
CPack package description file:
"/home/danlipsa/projects/uvcdat/src/docs/README.txt" could not be found.
Call Stack (most recent call first):
/usr/local/share/cmake-3.5/Modules/CPack.cmake:427 (cpack_check_file_exists)
CMakeLists.txt:849 (include)

CMake Error at /usr/local/share/cmake-3.5/Modules/CPack.cmake:423 (message):
CPack license resource file:
"/home/danlipsa/projects/uvcdat/src/docs/Legal.txt" could not be found.
Call Stack (most recent call first):
/usr/local/share/cmake-3.5/Modules/CPack.cmake:428 (cpack_check_file_exists)
CMakeLists.txt:849 (include)

-- Configuring incomplete, errors occurred!

[aashish24]

@danlipsa yes, seems like it, I will push a fix shortly. Thanks @doutriaux1