Clarify the Bootstrap docs notice with the dropdownParent option
Clarify the Bootstrap docs notice with the dropdownParent option

This closes https://github.com/select2/select2/pull/4253.

select2/select2,NabiKAZ/select2,michael-brade/select2,iestruch/select2,ZaArsProgger/select2,inway/select2,iestruch/select2,michael-brade/select2,fk/select2,inway/select2,select2/select2,bottomline/select2,ZaArsProgger/select2,bottomline/select2,NabiKAZ/select2,fk/select2