TypeScript Guidelines - Types: Inference, Annotations, Assertions, Escape Hatches (#74)

## Motivation

In order to improve type safety and maintainability, we need to
establish clear guidelines regarding how to apply types: specifically,
when and when not to use explicit type declarations or keywords such as
`as`, `any`.

## Explanation

- See markdown preview: [TypeScript Guidelines - "Types"
section](https://github.com/MetaMask/contributor-docs/blob/240206-typescript-guidelines-any-as/docs/typescript.md)
- ~The merge conflicts with main will be resolved after the review
process to avoid noisy diffs.~
- All examples are tagged with a permalink for easy reference and
quotation.

### Table of Contents
- Types
  - Type Inference
  - Type Annotations (`:`, `satisfies`)
  - Type Assertions (`as`, `!`)
  - Escape Hatches (`any`, `@ts-expect-error`)
    
### Details
- Dangers and advantages.
- Tips for avoiding.
- Acceptable use cases.

## References
- Closes #47
- Closes #57 
- Contributes to #69

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Co-authored-by: Mark Stacey <[email protected]>
Co-authored-by: Elliot Winkler <[email protected]>

Author: 3 people