Add seealso admonition

Author: Kevin Paul

sphinx_pythia_theme/static/css/pythia.css

@@ -103,6 +103,7 @@ div.admonition.important {
 
 div.admonition.attention,
 div.admonition.caution,
+div.admonition.seealso,
 div.admonition.warning {
   color: #836839;
   border-color: #fbeed5;