Update change note to new format

Author: atorralba

java/change-notes/2021-06-17-tainted-field-read-step-on-entrypoint-types.md renamed to java/ql/lib/change-notes/2021-12-15-tainted-field-read-step-on-entrypoint-types.md

@@ -1,2 +1,4 @@
-lgtm,codescanning
+---
+category: majorAnalysis
+---
 * Data flow now propagates taint from remote source `Parameter` types to read steps of their fields (e.g. `tainted.publicField` or `tainted.getField()`). This also applies to their subtypes and the types of their fields, recursively.