Separate examples from library source

[jatkinson1000]

We should separate the examples from the key source files in the library.

Perhaps into an /examples directory?

[jatkinson1000]

This opens the question where we put the pt2ts.py file.
Perhaps we also need a /tools directory?

[mondus]

This should cover more general restructuring. Suggest;

• include: (header files)
• src: source. Could combine header and source given simplicity of library. This will depend on if ftorch.f90 works like a c header file?
• utils: The p2ts2.py file
• docs: user documentation (not API docs)