add attribution for Mary Gathoni

Author: mr-c

.zenodo.json

@@ -36,7 +36,7 @@
             "name": "Ngumih Fien"
 	},
 	{
-            "name": "gathoni-k"
+            "name": "Mary Gathoni"
 	},
 	{
             "name": "Henry Liu"

AUTHORS.md

@@ -8,7 +8,7 @@ Thank you to the following contributors (in alphabetical order by user name):
 * Eugene Miloslavsky (@emiloslavsky)
 * Robin Long (@longr) <https://orcid.org/0000-0003-2249-645X>
 * Ngumih Fien (@Fienne)
-* @gathoni-k
+* Mary Gathoni (@gathoni-k)
 * Henry Liu (@HenryLiu0)
 * Marijke J. van Baren (@Jeltje)
 * @jessMaia