Add documentation for getting started with custom plugins

[adierkens]

While we have many plugins to use as implementation examples, I'd like the documentation to also have an on-boarding guide to writing a custom plugin

[nsinghal12]

@adierkens I'd like to work on this.

[nsinghal12]

@adierkens I have raised PR #67 to gather early feedback to see if there are directional changes required.

[adierkens]

🚀 Issue was released in v0.1.6 🚀

[adierkens]

🚀 Issue was released in v0.1.6 🚀