Wiki widget for terminal recordings created

TDF wiki now has a widget for embedding SVG animations rendered from 
terminal recordings: https://wiki.documentfoundation.org/Widget:Svganimation

Widgets can only be created and edited by administrators due to the 
obvious security issues arising from allowing the inclusion of freeform 
JavaScript and HTML. Similarly, SVGs with <script> elements are not 
allowed to be uploaded. Therefore, to be able to use the player controls 
for the animations, I created a Python script that moves the animation 
data into a comment in the SVG.

Terminal recordings are a nice way to show new contributors how to set 
something up. The fact that you can select and copy text from them is 
convenient. The recording and editing process is also probably simpler 
for many people compared to a video-based screen recorder.

Ilmari