Update release notes wrt #647

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -240,3 +240,8 @@ Oleksandr Poslavskyi (alevskyi@github)
 James Agnew (jamesagnew@github)
   * Contributed implementation of #611: Optionally allow leading decimal in float tokens
   (2.11.0)
+
+Pavel Krutikhin (pakru@github)
+  * Contributed fix for #647: Fix NPE in `writeNumber(String)` method of `UTF8JsonGenerator`,
+  `WriterBasedJsonGenerator`
+  (2.11.4)

release-notes/VERSION-2.x

@@ -16,6 +16,12 @@ JSON library.
 
 2.12.0 (not yet released)
 
+2.11.4 (not yet released)
+
+#647: Fix NPE in `writeNumber(String)` method of `UTF8JsonGenerator`,
+  `WriterBasedJsonGenerator`
+ (contributed by Pavel K)
+
 2.11.3 (02-Oct-2020)
 2.11.2 (02-Aug-2020)
 2.11.1 (25-Jun-2020)