Big ol' refresh

[banterability]

• Bump node version
• Drop all runtime dependencies
• Move CI from CircleCI to GitHub
• Flatten out test dir

[Copilot]

Pull Request Overview

This PR refreshes the project setup by bumping the Node.js version, removing runtime dependencies, migrating CI to GitHub Actions, and flattening the test directory.

• Bumps the Node.js version in .nvmrc
• Removes the md5 dependency and updates index.js to use crypto
• Migrates CI from CircleCI to GitHub Actions and flattens test files

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
package.json	Removes runtime dependency and test directory setting
index.js	Updates implementation to use crypto for hashing
index.test.js	Introduces flattened test file for blueshift functionality
tests/known_values.json	Removes redundant test data
tests/index_test.js	Removes duplicate test file
.nvmrc	Bumps Node version from v16.15.0 to v22
.github/workflows/ci.yml	Adds GitHub Actions configuration for CI
.circleci/config.yml	Removes CircleCI configuration

[Copilot]

Declare KNOWN_COLORS using 'const' (or 'let') instead of an implicit global assignment to ensure proper variable scoping and immutability.

Suggested change

	KNOWN_COLORS = {
	const KNOWN_COLORS = {