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README.md

@@ -9,8 +9,16 @@ Performs PCA with optional graph distance for neighborhood composition.
 
 (Still under heavy development.)
 
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+**Table of Contents**
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+- [Installation](#installation)
+- [Example](#example)
+  - [Classic PCA](#classic-pca)
+  - [Graph PCA](#graph-pca)
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 # Installation