fix typo chapter 8 readme

Author: lfunderburk

ch8/README.md

@@ -10,5 +10,5 @@ Exercises for Chapter 8. "Hands-on projects"
 2. [Perform text classification and sentiment analysis](./text-classification/) - this folder contains three sample applications of text classification:
     * [Evaluating Haystack's text classification component on a labelled dataset with categorized news](./text-classification/text-classification.ipynb)
     * [Building a custom component to classify news articles retrieved from web search](./text-classification/classification-with-haystack-search-pipeline.ipynb)
-    * [Building a custom component to perform sentioment analysis on Yelp reviews](./text-classification/sentiment_analysis.ipynbß)
+    * [Building a custom component to perform sentiment analysis on Yelp reviews](./text-classification/sentiment_analysis.ipynbß)
 3. [Build a chatbot or virtual assistant](./chatbot-virtual-assistant/)