fix(cite): added missing keywords section

Author: TomMonks

CITATION.cff

@@ -13,9 +13,10 @@ authors:
     affiliation: University of Exeter
     orcid: 'https://orcid.org/0000-0003-2631-4481'
 repository-code: 'https://github.com/TheOpenScienceNerd/replications-algorithm'
+keywords:
   - discrete-event simulation
   - simpy
   - python
   - open science
   - simopt
-license: MIT
+license: MIT