add semantic textual similarity tutorial

Author: x4nth055

README.md

@@ -58,6 +58,7 @@ This is a repository of all the tutorials of [The Python Code](https://www.thepy
         - [Fake News Detection using Transformers in Python](https://www.thepythoncode.com/article/fake-news-classification-in-python). ([code](machine-learning/nlp/fake-news-classification))
         - [Named Entity Recognition using Transformers and Spacy in Python](https://www.thepythoncode.com/article/named-entity-recognition-using-transformers-and-spacy). ([code](machine-learning/nlp/named-entity-recognition))
         - [Tokenization, Stemming, and Lemmatization in Python](https://www.thepythoncode.com/article/tokenization-stemming-and-lemmatization-in-python). ([code](machine-learning/nlp/tokenization-stemming-lemmatization))
+        - [How to Fine Tune BERT for Semantic Textual Similarity using Transformers in Python](https://www.thepythoncode.com/article/finetune-bert-for-semantic-textual-similarity-in-python). ([code](machine-learning/nlp/semantic-textual-similarity))
     - ### [Computer Vision](https://www.thepythoncode.com/topic/computer-vision)
         - [How to Detect Human Faces in Python using OpenCV](https://www.thepythoncode.com/article/detect-faces-opencv-python). ([code](machine-learning/face_detection))
         - [How to Make an Image Classifier in Python using TensorFlow and Keras](https://www.thepythoncode.com/article/image-classification-keras-python). ([code](machine-learning/image-classifier))