* Add Snell's Law implementation for refraction angle
* Add tests for Snell's Law calculations
* Update documentation with reference link to Snell's Law
Added a reference link to Snell's Law in the documentation.
* Prevent instantiation of SnellLaw class
Make SnellLaw class non-instantiable by adding a private constructor.
* Rename SnellsLawTest to SnellLawTest
* Refactor SnellLawTest for clarity and accuracy
* Rename SnellsLaw.java to SnellLaw.java
* Refactor SnellLawTest with additional assertions
* Refactor SnellLaw class constructor and error handling
Refactor SnellLaw constructor and error message formatting.
* Fix missing newline at end of SnellLawTest.java
Ensure that the SnellLawTest class has a newline at the end of the file.
* Simplify assertions in SnellLawTest
* Simplify exception throwing for total internal reflection
