feat!: termlink v2

[savioxavier]

Warning
This pull request contains BREAKING CHANGES

Note
This pull request proceeds to a "major" version: v2 v1.3.0

---

This pull request makes the following changes:

Hyperlink detection

• Hyperlink detection has been greatly improved
• New variables and variable checks have been introduced
• TERM_PROGRAM variable checking is stricter now, with the help of TERM_PROGRAM_VERSION constraints. This is a breaking change
• Multiple handling functions for environment variable detection such as hasEnv, checkAllEnvs, matchesEnv etc., have been added
• Version handling is now in a form of a struct called Version. parseVersion now returns this struct of three variables instead of three standalone variables called major, minor, and patch
• Version scanning now works with version that don't even contain dots
• os.Getenv() has been replaced with os.LookupEnv()
• termlink now respects the FORCE_HYPERLINK variable, and forces hyperlinks as long as the variable's value is any of []string{"1", "true", "always", "enabled"}
• Added support for more terminals including vscode and alacritty (possibly fixes Support alacritty #7)
• Added support for COLORTERM variable
• Fixed incorrect version condition for VTE_VERSION

Color Handling

• colorsList map now has integer values instead of strings
• Keys have been arranged according to their ANSI escape codes
• Detecting and adding valid colors from a termlink style color string has been refactored and simplified
• Colors are initially cleared upon entry to avoid redundant color codes
• parseColor("reset") has been replaced with an escape code to avoid additional processing

Dependencies

• fatih/color and jwalton/go-supportscolor have both been removed from the project. Checking for color support is unnecessary because this package only requires checking for basic colors. fatih/color wasn't used in the main termlink code anyways
• Currently, this package is dependency-free
• The only dependency is the assert testing library, which is only used for testing purposes and has no effect on main

Documentation

• godoc comments have been improved
• README.md has been modified with more code snippets and examples for other utilities such as SupportsHyperlinks and shouldForce

Examples

• examples/start.go has been improved with more examples and texts

Tests

• The test that included the fatih/color package has been removed
• Testing will be revamped in v2.1 v1.3.1 or in a future version (TODO)