Update release notes wrt #246

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -146,7 +146,10 @@ Michael Liedtke (mcliedtke@github)
 * Contributed fix for #212: (ion) Optimize `IonParser.getNumberType()` using
   `IonReader.getIntegerSize()`
  (2.12.0)
-
+* Contributed #246: (ion) Add `IonObjectMapper.builderForBinaryWriters()` / `.builderforTextualWriters()`
+  convenience methods
+ (2.12.2)
+ 
 Guillaume Bort (guillaumebort@github)
 
 * Contributed implementation of #222: (cbor) Add `CBORGenerator.Feature.LENIENT_UTF_ENCODING`

release-notes/VERSION-2.x

@@ -21,6 +21,9 @@ Modules:
  (contributed by jhhladky@github)
 #244: (ion) Add support for deserializing IonTimestamps and IonBlobs
  (contributed by jessbrya-amzn@github)
+#246: (ion) Add `IonObjectMapper.builderForBinaryWriters()` / `.builderforTextualWriters()`
+  convenience methods
+ (contributed by Michael L)
 #247: (ion) Enabling pretty-printing fails Ion serialization
 
 2.12.1 (08-Jan-2021)