Improve sensor locations tutorial (#9532)
Improve sensor locations tutorial (#9532)

* Improve sensor locations tutorial

* Implement review comments

* fix typo

Co-authored-by: Daniel McCloy <2591e5f46f28d303f9dc027d475a5c60d8dea17a@mccloy.info>
bloyl/mne-python,drammock/mne-python,Teekuningas/mne-python,Eric89GXL/mne-python,wmvanvliet/mne-python,kingjr/mne-python,kingjr/mne-python,drammock/mne-python,larsoner/mne-python,mne-tools/mne-python,wmvanvliet/mne-python,mne-tools/mne-python,olafhauk/mne-python,olafhauk/mne-python,Teekuningas/mne-python,larsoner/mne-python,larsoner/mne-python,pravsripad/mne-python,Teekuningas/mne-python,bloyl/mne-python,drammock/mne-python,pravsripad/mne-python,olafhauk/mne-python,mne-tools/mne-python,kingjr/mne-python,Eric89GXL/mne-python,pravsripad/mne-python,wmvanvliet/mne-python