Create a design goals and decisions page in the docs

A “Design Decisions and Goals” page serves as an essential resource for documenting the foundational principles and choices made during the development of the FS2-Queues library. This page provides clarity and transparency for users, contributors, and stakeholders, helping them understand the library’s purpose and guiding philosophy.

Proposed Structure for the Page:

1. Introduction: Brief overview of the library.
2. Design Goals: Key priorities while building it and what are our guiding stars while developing it.
3. Key Decisions: Explanation of significant design choices (e.g., why Cats-Effect integration was prioritized for example or why otel4s and circe).
4. Non-Goals: Areas the library does not aim to cover or explicitly avoids.