Document Cardano transactions signature and proving in website

[jpraynaud]

Why

We need to create a documentation page in the website that details how Cardano transactions are signed and how membership proofs are created.

What

Create a new page on the documentation website that explains the Cardano transactions signature and proving.

How

• [ ] Create a new documentation page explaining the Cardano transactions signature/proving
• [ ] Create a dev blog post?