Add short matplotlib tutorial on tudat-space

[Jérémie Gaffarel]

On the post-processing page of tudat-space, content could be added about how to make cleaner matplotlib plots.

This can include:

• The use of a grid.
• The use of a tight layout.
• The change of the font size.
• The change of line and marker size and style.
• The use of colormaps.
• The use and position of legends.