NoteElement missing in add_child_element

[kewashi]

Is your feature request related to a problem? Please describe.
In the add_child_element method each type of tag is checked and the appropriate class is used to instantiate the object, but the NoteElement tag is skipped, so all NOTE tags get added as a generic Element

Describe the solution you'd like
This is a simple fix I think. You just have to add a check for the NOTE tag and then use the NoteElement class. You also will need to include it as a dependency

Describe alternatives you've considered
My workaround was to make a local version of this function

[kewashi]

Typo above - the method that needs updating is new_child_element

I made a MyElement class that fixes this and imported it locally as a workaround.