fix: readme

[rjfonseca]

Fixes the README to better reflect the actual code and fixes some typos.

[Copilot]

Pull Request Overview

This PR fixes typos and updates the documentation in the README to accurately reflect the code usage. It also corrects a misspelled error message in the test file.

• Updated error message in dont_panic_test.go to fix a spelling error.
• Revised README.md to update error construction and improve documentation clarity.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
dont_panic_test.go	Corrected typo in error message to reflect the intended text.
README.md	Updated error construction example and clarified documentation changes.

Comments suppressed due to low confidence (1)

dont_panic_test.go:53

• Spelling error: 'unkown' should be corrected to 'unknown' in the error message.

	if op != opUnknownFunction {