add annotation primitives to compose module

[btel]

What

svg_utils is useful to add annotations to existing SVG images (or even bitmaps). For now, we are supporting a few annotation primitives (like lines, texts), but it would be nice to add a few more.

How

• add new classes in compose.py and transform.py files that implement Circles, Arrows, Rectangles, comics text cloud etc., you can follow the example of Text primitive
• add unit tests
• add a tutorial in the docs on annotating with SVG

for more info about SVG check out the mozilla tutorial:

https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial

https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial