Lemmy, Kbin, typo

- fix "Extentions" to "Extensions"
- fix "Forum" to "Forums" in the list of categories for Kbin
- add "Forums" to the list of categories for Lemmy

I've noticed Lemmy being described as a link aggregator, but
in practice I've only actually seen it being used as a forum,
so it seems fair to include it in "Forums".

source/_data/miscellaneous.json

@@ -71,7 +71,7 @@
         "zotClass": false,
         "diasporaClass": false,
         "OStatusClass": false,
-        "categories": ["Links"]
+        "categories": ["Forums", "Links"]
       },
       {
         "title": "microblog.pub",
@@ -1457,7 +1457,7 @@
         "zotClass": false,
         "diasporaClass": false,
         "OStatusClass": false,
-        "categories": ["Forum", "Links", "SN-mi"]
+        "categories": ["Forums", "Links", "SN-mi"]
       },
       {
         "title": "Takahe",

themes/starter/layout/miscellaneous.ejs

@@ -23,7 +23,7 @@ layout: layout
 
   const apps = site.data.miscellaneous.apps;
   const langList = langCount(apps).sort((a,b) => b.count - a.count);
-  const byCategory = [['snMacro', 'Social network (macro)'], ['snMicro', 'Social network (micro)'], ['blogPub', 'Blog and Publishing'], ['media', 'Media sharing'], ['links', 'Link sharing'], ['evMeet', 'Events and Meetups'], ['files', 'File hosting'], ['data', 'Open data'], ['reviews', 'Reviewing'], ['games', 'Gaming'], ['dev', 'Software development'], ['extend', 'Extentions'], ['forums', 'Forums, boards'], ['other', 'Other']];
+  const byCategory = [['snMacro', 'Social network (macro)'], ['snMicro', 'Social network (micro)'], ['blogPub', 'Blog and Publishing'], ['media', 'Media sharing'], ['links', 'Link sharing'], ['evMeet', 'Events and Meetups'], ['files', 'File hosting'], ['data', 'Open data'], ['reviews', 'Reviewing'], ['games', 'Gaming'], ['dev', 'Software development'], ['extend', 'Extensions'], ['forums', 'Forums, boards'], ['other', 'Other']];
   const byProtocol = [['sortDiaspora', 'diaspora'], ['sortZot', 'Zot'], ['sortAP', 'ActivityPub'], ['sortOstatus', 'OStatus']];
 %>