Update CITATION.cff

Author: drwilkins

CITATION.cff

@@ -6,6 +6,6 @@ authors:
     orcid: "https://orcid.org/0000-0002-3162-6749"
 title: "galacticpolymath/galacticEdTools: R Tools for K-16 Teaching"
 version: 0.1.3
+doi: 10.5281/zenodo.6563892
 date-released: 2021-12-18
 url: "https://galacticpolymath.github.io/galacticEdTools"
-doi: 10.5281/zenodo.6563892