docs(copm): Add sequence diagrams for COPM primitives

[jenniferlianne]

Primary change: adds mermaid sequence diagrams for how COPM primitives are used in asset transfer, asset exchange, and data sharing to copm-core README

Secondary change: adds TOC and reformats urls to links.

Pull Request Requirements

• Rebased onto upstream/main branch and squashed into single commit to help maintainers review it more efficient and to avoid spaghetti git commit graphs that obfuscate which commit did exactly what change, when and, why.
• Have git sign off at the end of commit message to avoid being marked red. You can add -s flag when using git commit command. You may refer to this link for more information.
• Follow the Commit Linting specification. You may refer to this link for more information.

Character Limit

• Pull Request Title and Commit Subject must not exceed 72 characters (including spaces and special characters).
• Commit Message per line must not exceed 80 characters (including spaces and special characters).

A Must Read for Beginners
For rebasing and squashing, here's a must read guide for beginners.

[jagpreetsinghsasan]

@jenniferlianne interesting to know that we can use a plugin to render the sequence diagrams in the readme itself!

@petermetz shall this be moved to docs/architecture folder just like other packages and then referenced in the base Readme file?
Also, we can use the mermaid plugin in other packages as well (currently have the .puml code inside packages/PACKAGE_NAME/docs/architecture folder and then we refer to an image parsed from the same, in the docs. Can start with this included in the DAML package?)

[outSH]

Looks great, I'm ok with both keeping these diagrams here or moving them to docs as suggested by Jagpreet. I found one small typo though

[outSH]

Typo - should be ClaimLock

[jenniferlianne]

Thank you.