fix typo

index.md

@@ -22,8 +22,9 @@ The design of integrated digital systems encompassing both customized software a
 
 * [Lab 2: Using Spatial Controllers and Memories](lab2.md)
 
-* [Lab 3: Algorithm-Specific Hardware Design]
+* Lab 3: Algorithm-Specific Hardware Design
     * [Part1: Convolution](lab3_conv.md)
+    * [Part2: Vitis-Spatial Hello World]()
 
 <!-- **Laboratory Links:**
 

lab3_conv.md

@@ -32,7 +32,7 @@ This is executed as:
     <img src="./img/sobel-conv-kernels.gif" width="30%">
 </div>
 
-3. Given that `horz` and `vert` is the result of the convolution operation of each kernel, store the sum of the absolute values to the output. The value should be sqrt(`horz`<sup>2</sup> + `vert`<sup>2</sup>), but this can be approximated with |`horz`| + |`vert`|. To learn more about sobel filters, you can take a look at [this page](https://homepages.inf.ed.ac.uk/rbf/HIPR2/sobel.htm).
+3. Given that `horz` and `vert` is the result of the convolution operation of each kernel, store the sum of the absolute values to the output. The value should be sqrt(`horz`<sup>2</sup> + `vert`<sup>2</sup>), but this can be approximated with `|horz| + |vert|`. To learn more about sobel filters, you can take a look at [this page](https://homepages.inf.ed.ac.uk/rbf/HIPR2/sobel.htm).
 
 
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