Fixing a few typos (qiskit-community#1331)

I'd appreciate if a native English speaker can verify that the fixes are
correct.

Author: yaelbh

docs/tutorials/calibrations.rst

@@ -196,8 +196,8 @@ Run the calibration experiment:
 
 The instance of ``calibrations`` has been automatically updated with the measured
 frequency, as shown below. In addition to the columns shown below, ``calibrations`` also
-store the group to which a value belongs, whether a values is valid or not and the
-experiment id that produce a value.
+stores the group to which a value belongs, whether a value is valid or not, and the
+experiment id that produced a value.
 
 .. jupyter-execute::
 

qiskit_experiments/calibration_management/__init__.py

@@ -23,7 +23,7 @@
     otherwise indicated.
 
 Calibrating qubit setups is the task of finding the pulse shapes and parameter
-values that maximizes the fidelity of the resulting quantum operations. This
+values that maximize the fidelity of the resulting quantum operations. This
 therefore requires experiments which are analyzed to extract parameter values.
 Furthermore, the resulting parameter values and schedules must be managed. The
 calibration management module in Qiskit experiments allows users to manage