use mermaid instead of SVG for diagram

[inkade]

Swapped the diag.svg for diagram using mermaid for enhanced ease of use, version control and collaboration.

[oxinabox]

I'm not sure.
That SVG was more an illustrative logo than an actual diagram showing something really meaningful.
The mermaid is indeed more maintainable, but it hasn't needed any maintainance yet
and the SVG is maybe prettier?

[inkade]

Absolutely, I should have perhaps caveated that this was more of a suggestion and I recognise that it is very much subject to opinion. No issues here if it doesn't merge :)