Refactor package and documentation

This version makes the package usable by importing modules to run solvers instead of including monolithic scripts.
This allow for a much better structure a modular usage.

Other features added:

• Tests against analytical solutions
• Fully fledged documentation using Documenter.jl is also now available here.

NOTE: legacy solvers sripts are still inside the scripts folder.

Very first project release

v1.0.0

Very first version of the project