Added a plot to the SymPy lab.
Also reordered it a little.
Merge pull request #231 from insertinterestingnamehere/sympy

Added a plot to the SymPy lab.
Changed file display in 'Getting started' to match lstlisting environment.
Reformatted the change of basis lab.
Some revision of the change of basis lab.
Further revision of the change of basis lab.
Merge pull request #232 from insertinterestingnamehere/typos

Revision of the change of basis lab.