chore: add custom-timeout example

[angeloashmore]

Types of changes

• Chore (a non-breaking change which is related to package maintenance)
• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

This PR adds an example demonstrating how to add a custom request timeout duration. It implements it using an AbortController and setTimeout().

See: #129

Checklist:

• My change requires an update to the official documentation.
• All TSDoc comments are up-to-date and new ones have been added where necessary.
• All new and existing tests are passing.

🐢

[lihbr]

Looks good to me, since fetch implementation can now be provided it's now the duty of the fetch implementation to handle any kind of timeout.

Moving forward with it 🚀