Rewrite `scripts/generate-component-docs.rb` in Rust

[pront]

Code is here: https://github.com/vectordotdev/vector/blob/master/scripts/generate-component-docs.rb

Longe term we want to remove the dependency to Ruby and generally we have had a great experience with Rust utilities.

[titaneric]

I would like to investigate this issue, and take a deep dive into https://github.com/vectordotdev/vector/blob/master/scripts/generate-component-docs.rb

I find the partial WIP code in https://github.com/vectordotdev/vector/blob/master/lib/docs-renderer/src/main.rs . Since it is really complicated, I might need LOTS of time to verify the docs generation and write the unit test for it.

[pront]

Hi @titaneric, thank you for your interest in this and for all work you already did. Obviously there is no rush at all. I expect that removing Ruby will be a time consuming effort (but maybe also fun). Feel free to experiment as much as you want and you can ping me here if you need input.