[weeding_lines] extension

[vmario89]

Let's create a weeding lines generator extension -> see https://stadtfabrikanten.org/display/IFM/Weeding+lines+with+Inkscape for what weeding lines are

We could create weeding lines:

• horizontal
• vertical
• in an defined angle
• circular from the outside
• like some offset path (we could use offset_paths extension -> https://github.com/eridur-de/mightyscape-1.2/tree/master/extensions/fablabchemnitz/offset_paths)

Could be done by shapely and "split lines at intersections" extension as base code