Add change note

Author: atorralba

java/ql/lib/change-notes/2023-03-20-dataflow-models.md

@@ -0,0 +1,10 @@
+---
+category: minorAnalysis
+---
+* Added more sink and summary dataflow models for the following packages:
+  * `java.net`
+  * `java.nio.file`
+  * `javax.imageio.stream`
+  * `javax.naming`
+  * `javax.servlet`
+  * `org.geogebra.web.full.main`