We should add crossrefs in the info docstring to the various MNE functions/methods that can safely change info fields (e.g., inst.rename_channels etc)

• mne.{io.Raw | Epochs | Evoked}.add_proj
• mne.{io.Raw | Epochs | Evoked}.del_proj
• mne.{io.Raw | Epochs | Evoked}.set_channel_types
• mne.{io.Raw | Epochs | Evoked}.set_meas_date