Update history.txt

Author: IllianiBird

MekHQ/docs/history.txt

@@ -32,6 +32,7 @@ MEKHQ VERSION HISTORY:
 + PR #6359: Fixed Missing Scenarios 
 + PR #6358: Fixed Fatigue Status Report Update Messages
 + PR #6372: Enabled MekHQ Prisoner Capture Style for Non-AtB, Non-StratCon Campaigns
++ PR #6375: Moved and Renamed Immersive Dialog Base Classes
 
 0.50.04 (2025-03-22 1600 UTC)
 + PR #5852: RAW CamOps Delivery Times