feat: add gradient and theme features with corresponding tests and documentation

examples/theme.js

@@ -0,0 +1,34 @@
+import chalk from '../source/index.js';
+
+// Set color level to enable colors (adjust based on terminal support)
+chalk.level = 3;
+
+// Define a custom theme with named styles
+const themedChalk = chalk.theme({
+	error: chalk.red.bold,
+	success: chalk.green,
+	warning: chalk.yellow.underline,
+	info: chalk.blue,
+	title: chalk.magenta.bold.underline,
+});
+
+// Demonstrate the theme in action
+console.log(themedChalk.title('Chalk Theme Example'));
+console.log(); // Empty line
+
+console.log(themedChalk.error('This is an error message'));
+console.log(themedChalk.success('This is a success message'));
+console.log(themedChalk.warning('This is a warning message'));
+console.log(themedChalk.info('This is an info message'));
+console.log(); // Empty line
+
+// Show that original styles still work
+console.log(themedChalk.red('Still works with original styles'));
+console.log(themedChalk.bold('Bold text from themed chalk'));
+
+// Demonstrate chaining with theme styles
+console.log(themedChalk.error.bgWhite('Error on white background'));
+console.log(themedChalk.success.underline('Underlined success'));
+
+console.log();
+console.log(themedChalk.title('Theme Complete!'));