Slight errors and typos in documentation

[Musab1Blaser]

There are various slight errors in documentation grammar/writing consistency.
e.g. Extented Kalman Filter instead of Extended Kalman Filter
in https://atsushisakai.github.io/PythonRobotics/modules/0_getting_started/2_how_to_run_sample_codes.html#steps-to-setup-and-run-sample-codes