Update README.md for 2.x release

[rudrankriyam]

Summary

• Updated template counts from 63 to 237 total templates (44+88+105) to match current implementation
• Fixed API examples to include animationSpeed parameter and PredefinedTemplate enum usage
• Added documentation for new AnimationPattern and PointAnimation features with examples
• Updated Swift version requirement from 6.0+ to 6.2+ to match Package.swift specifications
• Reorganized template documentation to be more scalable with programmatic exploration methods
• Added advanced animation examples including speed control and noise effect combinations
• Fixed typo in custom gradients section

Test plan

• Verify all code examples compile with current API
• Confirm template counts match actual implementation
• Test that all documented features work as described
• Check that Swift version requirements match Package.swift