docs: update readme usage

README.md

@@ -12,9 +12,50 @@ You can install the codemods using npm or yarn:
 npm install @e18e/web-features-codemods --save-dev
 ```
 
+## Available Codemods
+
+| Codemod | Description | Example |
+|---------|-------------|---------|
+| `arrayAt` | Convert array length-based indexing to `at()` method | `array[array.length - 1]` → `array.at(-1)` |
+| `arrayFill` | Optimize array fill patterns | Various fill pattern optimizations |
+| `arrayIncludes` | Convert `indexOf` checks to `includes()` | `array.indexOf(item) !== -1` → `array.includes(item)` |
+| `arrayToReversed` | Convert copy-and-reverse patterns to `toReversed()` | `array.slice().reverse()` → `array.toReversed()` |
+| `arrayToSorted` | Convert copy-and-sort patterns to `toSorted()` | `array.slice().sort()` → `array.toSorted()` |
+| `arrayToSpliced` | Convert copy-and-splice patterns to `toSpliced()` | `array.slice().splice(...)` → `array.toSpliced(...)` |
+| `exponentiation` | Convert `Math.pow()` to exponentiation operator | `Math.pow(base, exp)` → `base ** exp` |
+| `nullishCoalescing` | Convert null/undefined checks to nullish coalescing | `value != null ? value : default` → `value ?? default` |
+| `objectHasOwn` | Convert `hasOwnProperty` to `Object.hasOwn()` | `obj.hasOwnProperty(prop)` → `Object.hasOwn(obj, prop)` |
+| `postcssSignFunctions` | Remove imports for `postcss-sign-functions` polyfill | Removes obsolete polyfill imports |
+| `spreadSyntax` | Convert array/object methods to spread syntax | `array.concat(other)` → `[...array, ...other]` |
+| `stringIncludes` | Convert `indexOf` checks to `includes()` | `string.indexOf(substr) !== -1` → `string.includes(substr)` |
+| `urlCanParse` | Convert URL validation try-catch to `URL.canParse()` | `try { new URL(url) } catch { }` → `URL.canParse(url)` |
+
 ## Usage
 
-TBD
+Each codemod can be imported and used programmatically. All codemods implement the same interface with `test()` and `apply()` methods.
+
+### Basic Example
+
+```javascript
+import {arrayAt} from '@e18e/web-features-codemods';
+
+const sourceCode = `
+const lastItem = myArray[myArray.length - 1];
+const firstItem = myArray[0];
+`;
+
+// Optionally check if the codemod applies to this source.
+// You can also skip this step and directly call apply() as non-matching
+// codemods will simply return the original source.
+if (arrayAt.test({source: sourceCode})) {
+  // Apply the transformation
+  const transformed = arrayAt.apply({source: sourceCode});
+  console.log(transformed);
+  // Output:
+  // const lastItem = myArray.at(-1);
+  // const firstItem = myArray[0];
+}
+```
 
 ## License