Added name to .mailmap

Author: ChrisPaulBennett

.mailmap

@@ -58,3 +58,4 @@ github-actions[bot]        <github-actions@noreply.github.com>
 github-actions[bot]        <github-actions@noreply.github.com>  GitHub Action
 Diquan Jabbour             <165976689+Diquan-BOM@users.noreply.github.com>
 Maxime Rio                 <maxime.rio@niwa.co.nz>
+Christoper Bennett         <christopher.bennett@metoffice.gov.uk>