extract tidy-tree layout into separate package

on-behalf-of: @Mermaid-Chart <hello@mermaidchart.com>

packages/mermaid-layout-tidy-tree/src/index.ts

@@ -0,0 +1,50 @@
+/**
+ * Bidirectional Tidy-Tree Layout Algorithm for Generic Diagrams
+ *
+ * This module provides a layout algorithm implementation using the
+ * non-layered-tidy-tree-layout algorithm for positioning nodes and edges
+ * in tree structures with a bidirectional approach.
+ *
+ * The algorithm creates two separate trees that grow horizontally in opposite
+ * directions from a central root node:
+ * - Left tree: grows horizontally to the left (children alternate: 1st, 3rd, 5th...)
+ * - Right tree: grows horizontally to the right (children alternate: 2nd, 4th, 6th...)
+ *
+ * This creates a balanced, symmetric layout that is ideal for mindmaps,
+ * organizational charts, and other tree-based diagrams.
+ *
+ * The algorithm follows the unified rendering pattern and can be used
+ * by any diagram type that provides compatible LayoutData.
+ */
+
+/**
+ * Render function for the bidirectional tidy-tree layout algorithm
+ *
+ * This function follows the unified rendering pattern used by all layout algorithms.
+ * It takes LayoutData, inserts nodes into DOM, runs the bidirectional tidy-tree layout algorithm,
+ * and renders the positioned elements to the SVG.
+ *
+ * Features:
+ * - Alternates root children between left and right trees
+ * - Left tree grows horizontally to the left (rotated 90° counterclockwise)
+ * - Right tree grows horizontally to the right (rotated 90° clockwise)
+ * - Uses tidy-tree algorithm for optimal spacing within each tree
+ * - Creates symmetric, balanced layouts
+ * - Maintains proper edge connections between all nodes
+ *
+ * Layout Structure:
+ * ```
+ * [Child 3] ← [Child 1] ← [Root] → [Child 2] → [Child 4]
+ *     ↓           ↓                     ↓           ↓
+ * [GrandChild]  [GrandChild]      [GrandChild]  [GrandChild]
+ * ```
+ *
+ * @param layoutData - Layout data containing nodes, edges, and configuration
+ * @param svg - SVG element to render to
+ * @param helpers - Internal helper functions for rendering
+ * @param options - Rendering options
+ */
+export { default } from './layouts.js';
+export * from './types.js';
+export * from './layout.js';
+export { render } from './render.js';