Docs for Task provider creation

#1

We provide docs for anyone who want to start creating their custom Task Provider at https://docs.opencatapult.net/guides/dev-guides/create-task-provider.

The guidance is broken down into 4 parts to make it easier to follow. Each part contains more knowledge, tips n tricks, gotchas, and anything else related to the Task Provider creation.

Please let me know your feedback so we can improve it to make it even easier to follow.

@brain.konasara please feel free to share anything related to this topic here. Thanks!