update mmistakes theme

_config.yml

@@ -10,7 +10,7 @@
 # Review documentation to determine if you should use `theme` or `remote_theme`
 # https://mmistakes.github.io/minimal-mistakes/docs/quick-start-guide/#installing-the-theme
 
-remote_theme             : "nuclearphoenixx/minimal-mistakes@4.24.2"
+remote_theme             : "mmistakes/minimal-mistakes@4.25.0"
 minimal_mistakes_skin    : "air" # "default", "air", "aqua", "contrast", "dark", "dirt", "neon", "mint", "plum
 
 # Site Settings
@@ -28,6 +28,8 @@ logo                     : "/assets/images/opengamma.png" # path of logo image t
 masthead_title           : # overrides the website title displayed in the masthead, use " " for no title
 # breadcrumbs            : false # true, false (default)
 words_per_minute         : 200
+copyright                : # "copyright" name, defaults to site.title
+copyright_url            : # "copyright" URL, defaults to site.url
 comments:
   provider               : # false (default), "disqus", "discourse", "facebook", "staticman", "staticman_v2", "utterances", "giscus", "custom"
   disqus: