[DOC] Introducing Quick Start Guide to PL/pgSQL and PL/Python Documentation

Hi

I have made some documentation enhancements for PL/pgSQL and PL/Python
sections. The changes include the addition of a Quick Start Guide to
facilitate a smoother onboarding experience for users.

Patch File Name:
0001-plpyhton-plpgsql-docu-changes.patch

Patch Description:
This patch introduces a Quick Start Guide to the documentation for PL/pgSQL
and PL/Python. The Quick Start Guide provides users with a step-by-step
walkthrough of setting up and using these procedural languages. The goal is
to improve user accessibility and streamline the learning process.

Changes Made:
1. Added a new section titled "Quick Start Guide" to both PL/pgSQL and
PL/Python documentation.
2. Included step-by-step instructions for users to get started with these
procedural languages.
3. Provided explanations, code snippets, and examples to illustrate key
concepts.

Discussion Points:
I am seeking your feedback on the following aspects:
- Clarity and completeness of the Quick Start Guide
- Any additional information or examples that could enhance the guide
- Suggestions for improving the overall documentation structure

Your insights and suggestions are highly valuable, and I appreciate your
time in reviewing this documentation enhancement.

--
Best regards,
Ishaan Adarsh