Initial rfc for code standards

[Voxelot]

This PR includes a RFC describing the process for submitting future coding standard RFCs.

It also includes the following changes:

• New build script for mdbook (borrowed from Rust RFCs) to enable autogeneration of the summary so that it is always up-to-date with any rfcs added to the /text/ folder.
• Code Standards section of the book. If any RFCS are made to change the coding standards, that PR should also directly update the appropriate sections in the code-standards book to reflect the RFC outcome.
• Some very rudimentary initial code standards around linting, security audits, semver, api design guidelines and logging.

[vlopes11]

Small nit

[vlopes11]

Suggestion: include #![warn(missing_docs)] as mandatory for all crates.

Considering warning are blockers for the CI, then this should make at least some basic documentation mandatory