message: Update configuring-superset.mdx
  Fixes typo dateime -> datetime
diff: @@ -285,7 +285,7 @@ change and define a grace period end date (exclusive of course) after which all
  to the [start, end) interval.
  ```python
  -from dateime import date
  +from datetime import date
  SIP_15_ENABLED = True
  SIP_15_GRACE_PERIOD_END = date(<YYYY>, <MM>, <DD>)
  