onsets_to_dm() weighting functionality

[ljchang]

@ejolly does the onsets_to_dm() have the ability to add weights? Sometimes we may want to weight the intensity of a value something other than 1, such as parametric modulation designs. Just wanted to check if that was possible or if I was missing something.

[ejolly]

Not currently, you'd have to do it after-the-fact, but could consider adding it as an enhancement