Feat: Sequnce Diagram SVGs into Mermaid renders

[hanzalahwaheed]

Fixes #792

I've tried to convert the diagrams into mermaid renders. Here are the tow outputs that I have. Need help choosing the better one.

serial coupling diagram

reference: https://precice.org/couple-your-code-coupling-flow.html

original screenshot

mermaid render A

This is a more direct one-to-one mapping of the diagram.

mermaid render B

This is a more semantic render.

@MakisH which one do you think is a better render? I'm inclined towards A but the loop box of B is also nice.

[MakisH]

Thank you @hanzalahwaheed, this is useful. We will eventually review it and see how it might work together with other documentation as well.