Initial release of edgy tools

[boessu]

I tried to make an initial adaption to PlantUML as an edgy tool.

• I tried to use the recommendations and guidelines in https://plantuml.com/en/preprocessing. However, I'm not always sure if I understood that correctly. E.g. all procedures do have a leading $ now, which seems to be a novum within the stdlib?!
• The sprites are SVG based. I think this is the 1st stdlib which uses this feature.
• I'm not that experienced in this area... please help if I didn't understand something correctly (and sorry for noob errors in contribution...).