Update index.md

contrib/numpy/index.md

@@ -1,12 +1,5 @@
 # List of sections
 
-* [Basic Mathematics](#BasicMaths)
-   * [What is a Matrix?](#Matrix-Intro)
-   * [Scalars and Vectors](#Scalars-Vectors)
-   * [Arrays in Python](#Arrays)
-   * [What is a Tensor?](#Tensors)
-   * [Addition and Subtraction in Matrices](#Arithmetic)
-   * [Transpose of Matrices & Vectors](#Transpose)
-   * [Dot Product](#DotProduct)
-   * [Dot Product of Matrices](#DotMatrices)
+* [Basic Mathematics](basic_math.md)
+