update History.rst

Author: qroa

HISTORY.rst

@@ -12,6 +12,7 @@ History
 * Fix issue 528 to correct broken ENS image in the documentation
 * Fix issue 548 to correct labels generated in tutorial
 * Fix issue 547 to fix wrong warning
+* Refactored `MapieQuantileRegressor` fit into `prefit_estimators`, `fit_estimators`, and `conformalize` for improved modularity.
 
 0.9.1 (2024-09-13)
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