Add known issues to changelog and readme (#3722)

CHANGELOG.md

@@ -96,7 +96,7 @@ All notable changes to this project will be documented in this file.
 - Refactoring detection modules
   (<https://github.com/openvinotoolkit/training_extensions/pull/3636>)
 
-### Buf fixes
+### Bug fixes
 
 - Fix conflicts between develop and 2.0.0
   (<https://github.com/openvinotoolkit/training_extensions/pull/3490>)
@@ -139,6 +139,10 @@ All notable changes to this project will be documented in this file.
 - Fix MaskRCNN SwinT NNCF Accuracy Drop
   (<https://github.com/openvinotoolkit/training_extensions/pull/3685>)
 
+### Known issues
+
+- Post-Training Quantization (PTQ) optimization applied to maskrcnn_swint in the instance segmentation task may result in significantly reduced accuracy. This issue is expected to be addressed with an upgrade to OpenVINO and NNCF in a future release.
+
 ## \[v2.0.0\]
 
 > _**NOTES**_

README.md

@@ -221,7 +221,7 @@ In addition to the examples above, please refer to the documentation for tutoria
 - Move assigning tasks to Models from Engine to Anomaly Model Classes
 - Refactoring detection modules
 
-### Buf fixes
+### Bug fixes
 
 - Fix conflicts between develop and 2.0.0
 - Fix polygon mask
@@ -244,6 +244,10 @@ In addition to the examples above, please refer to the documentation for tutoria
 - Fix optimize with Semi-SL data pipeline
 - Fix MaskRCNN SwinT NNCF Accuracy Drop
 
+### Known issues
+
+- Post-Training Quantization (PTQ) optimization applied to maskrcnn_swint in the instance segmentation task may result in significantly reduced accuracy. This issue is expected to be addressed with an upgrade to OpenVINO and NNCF in a future release.
+
 ### Release History
 
 Please refer to the [CHANGELOG.md](CHANGELOG.md)