"For example, we want input behavior for RTL languages such as Arabic and Hebrew to meet users' expectations. We also want to be able to support editor contents with a mixture of LTR and RTL text.
To that end, Draft uses a bidi algorithm to determine appropriate text alignment and direction on a per-block basis.
Text is rendered with an LTR or RTL direction automatically as the user types. You should not need to do anything to set direction yourself."