Add eif heatmap plots to README.md (#82)

* Add Standard IF vs Extended IF score heatmap plots to README

Add synthetic 2D score heatmaps illustrating the axis-aligned bias of
Standard Isolation Forest that Extended Isolation Forest eliminates.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Update heatmap plots with improved versions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Update heatmap plots

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Update heatmap plots

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jverbus

README.md

@@ -254,6 +254,23 @@ Use `ExtendedIsolationForest` instead of `IsolationForest` when:
 The standard `IsolationForest` remains a good default for high-dimensional, uncorrelated data where
 axis-aligned splits are sufficient and computational cost matters.
 
+The following heatmaps, produced using this library's `IsolationForest` and `ExtendedIsolationForest`
+implementations, illustrate the difference on synthetic 2D datasets. Standard IF exhibits
+axis-aligned artifacts (visible as cross-shaped high-score regions), while Extended IF eliminates
+this directional bias.
+
+<p align="center">
+<img src="./assets/single_blob_heatmap.svg" alt="Single Blob: Standard IF vs Extended IF" width="85%"/>
+</p>
+
+<p align="center">
+<img src="./assets/two_blobs_heatmap.svg" alt="Two Blobs: Standard IF vs Extended IF" width="85%"/>
+</p>
+
+<p align="center">
+<img src="./assets/sinusoid_heatmap.svg" alt="Sinusoid: Standard IF vs Extended IF" width="85%"/>
+</p>
+
 ### Extended Isolation Forest parameters
 
 `ExtendedIsolationForest` accepts all the same parameters as `IsolationForest` (see the