feature: add support for (simple) figure placement

[markdoerr]

Hi polylux developers,

slides are a mainly graphical medium, therefore it would be nice to support simple placement/scaling of figures next to text.
A grid system could be useful for this purpose (also to align figures).
If this already supported, please provide some examples for beginners.

Thanx :)

[andreasKroepelin]

Have you tried using #toolbox.side-by-side and #toolbox.big`?