Update README.md (#11078)

Co-authored-by: Luciano Bello <bel@zurich.ibm.com>

README.md

@@ -76,7 +76,7 @@ Running this will give an outcome similar to `{0: 0.497, 7: 0.503}` which is `00
 To illustrate the power of Estimator, we now use the quantum information toolbox to create the operator $XXY+XYX+YXX-YYY$ and pass it to the `run()` function, along with our quantum circuit. Note the Estimator requires a circuit _**without**_ measurement, so we use the `qc_example` circuit we created earlier.
 
 ```python
-# 2. define the observable to be measured 
+# 2. Define the observable to be measured 
 from qiskit.quantum_info import SparsePauliOp
 operator = SparsePauliOp.from_list([("XXY", 1), ("XYX", 1), ("YXX", 1), ("YYY", -1)])
 
@@ -165,4 +165,4 @@ We acknowledge partial support for Qiskit development from the DOE Office of Sci
 
 ## License
 
-[Apache License 2.0](LICENSE.txt)
+[Apache License 2.0](LICENSE.txt)