[Tooling] Add a GitHub bot to validate PR meta

[adshmh]

Objective

Streamline contributions by automating (or at-least pointing out the need for) the setting of PR meta, e.g. reviewers, project, labels, etc.

Origin Document

https://github.com/pokt-network/pocket/pull/773/files#r1203112450

Goals

• Make it easier to open issues/PRs for both new and existing contributors
• Open up the possibility of referring the issue/PR author to docs that may have been overlooked.

Deliverable

• A GitHub bot that looks for any missing PR/issue meta and adds a comment addressed to the author.
• Updated docs, based on https://github.com/pokt-network/pocket/pull/773/files#r1207219131, to which the bot points in its comments
• (Optional) Some automation of setting PR/issue meta: Assignee and Reviewers would be good starting points.

Non-goals / Non-deliverables

General issue deliverables

• Update any relevant local/global README(s)
• Update relevant source code tree explanations
• Add or update any relevant or supporting mermaid diagrams

Testing Methodology

• Task specific tests or benchmarks: make ...
• New tests or benchmarks: make ...
• All tests: make test_all

---

Creator: [@adshmh ]
Co-Owners: [@dylanlott @Olshansk @bryanchriswhite]

[Olshansk]

LGTM. Just updated the milestone from M4 to M*