Made mermaid into an npm dependency instead of built in

Author: flibbles

package-lock.json

@@ -7,7 +7,7 @@
     "doc": "docs"
   },
   "scripts": {
-    "build": "tiddlywiki ++node_modules/tw5-vis-network/plugins/vis-network --build index bundle",
+    "build": "tiddlywiki ++node_modules/tw5-vis-network/plugins/vis-network ++node_modules/mermaid-tw5/mermaid-tw5/plugins/mermaid-tw5 --build index bundle",
     "test": "tiddlywiki ++node_modules/tw5-relink/plugins/relink ++node_modules/tw5-relink/plugins/relink-fieldnames --build test"
   },
   "repository": {
@@ -33,6 +33,7 @@
   },
   "devDependencies": {
     "tw5-relink": "github:flibbles/tw5-relink",
-    "tw5-vis-network": "github:flibbles/tw5-vis-network#v10.5.4"
+    "tw5-vis-network": "github:flibbles/tw5-vis-network#v10.5.4",
+    "mermaid-tw5": "github:flibbles/mermaid-tw5"
   }
 }