Update docs/brainstim.rst, docs/eeg.rst, docs/modelling.rst, docs/brainstim/Participant_Report_of_Symptoms_v2_14012021.pdf, docs/brainstim/Brain_Stimulation_Safety_Report_v12.pdf, docs/brainstim/Sample_information_TUS.pdf, docs/brainstim/BRIC_TUS_safety_questionnaire.pdf