Fix: Add missing matplotlib installation in example code

README.md

@@ -53,6 +53,7 @@ pip install git+https://github.com/amazon-science/chronos-forecasting.git
 A minimal example showing how to perform inference using Chronos models:
 
 ```python
+!{sys.executable} -m pip install matplotlib
 import matplotlib.pyplot as plt
 import numpy as np
 import pandas as pd