correct typo's in READMEs

markov_chain_monte_carlo/README.md

 # This is the MCMC (Markov chain Monte Carlo) practical
 
-The practical is in Python. There is a Notebook versio (.ipynb file) and a Markdown version (.md).
+The practical is in Python. There is a Notebook version (.ipynb file) and a Markdown version (.md).
 
 To use the Notebook version, you need to start a jupyter notebook and open the file within the notebook.
 

simulation_based_inference/README.md

 # This is the SBI (Simulation Based Inference) practicals.
 
-The practical is in Python. There is a Notebook versio (.ipynb file) and a Markdown version (.md).
+The practical is in Python. There is a Notebook version (.ipynb file) and a Markdown version (.md).
 
 To use the Notebook version, you need to start a jupyter notebook and open the file within the notebook.