Reduce size of index.html

[kordwarshuis]

Reduce the size of index.html.

A generated index.html specification is about 1.9 MB.

This is bigger than what should be necessary.

To Do: analyze index.html and find the culprits.

[kordwarshuis]

One reason is that external specifications are included (not visible, via “display: none”). If the external specification has 500 terms, this starts to add up in kB.

[kordwarshuis]

Also, the “charts.js” library is extensive (in kB). The question is: who needs it?