Add missing asset to cabal file

Author: mpickering

eventlog2html.cabal

@@ -24,6 +24,7 @@ Build-type:          Simple
 Extra-source-files:
   javascript/**/*.js
   javascript/**/*.css
+  javascript/**/*.vg
   javascript/generated/vega-embed@6.14.0
   javascript/generated/vega@5.17.0
   javascript/generated/vega-lite@4.17.0