chore: New doc

Author: ayonious

docs/doc-transform.md

@@ -0,0 +1,65 @@
+---
+id: doc-transform
+title: Transform Functions
+sidebar_label: Transform Functions
+---
+
+import useBaseUrl from '@docusaurus/useBaseUrl';
+
+Transform functions allow you to format cell values before display without modifying the original data. This is useful for currency formatting, date conversion, string manipulation, and any other display transformations.
+
+## Basic String Transform
+
+```javascript
+import { Table } from 'console-table-printer';
+
+const p = new Table({
+  columns: [
+    { name: 'original', alignment: 'left' },
+    {
+      name: 'uppercase',
+      alignment: 'left',
+      // highlight-next-line
+      transform: (value) => String(value).toUpperCase()
+    },
+  ],
+});
+
+p.addRow({ original: 'hello', uppercase: 'hello' });
+p.addRow({ original: 'world', uppercase: 'world' });
+p.addRow({ original: 'test', uppercase: 'test' });
+
+p.printTable();
+```
+
+The `uppercase` column displays the transformed values while the original data remains unchanged.
+
+## Currency Formatting
+
+One of the most common use cases is formatting numbers as currency:
+
+```javascript
+import { Table } from 'console-table-printer';
+
+const p = new Table({
+  columns: [
+    { name: 'item', alignment: 'left' },
+    {
+      name: 'price',
+      alignment: 'right',
+      // highlight-next-line
+      transform: (value) => `$${Number(value).toFixed(2)}`
+    },
+  ],
+});
+
+p.addRows([
+  { item: 'Coffee', price: 3.5 },
+  { item: 'Sandwich', price: 7.99 },
+  { item: 'Water', price: 1 },
+]);
+
+p.printTable();
+```
+
+This transforms raw numbers like `3.5` into formatted currency like `$3.50`.

sidebars.js

@@ -7,6 +7,7 @@ module.exports = {
       "doc-row-divider",
       "doc-add-columns",
       "doc-color",
+      'doc-transform',
       "doc-no-ascii",
       "doc-sort-filter",
       "doc-alignment",