Consider using code from json-ld.org minutes for summary

[gkellogg]

The json-ld.org/minutes summary page includes topics and resolutions for all meetings, rather than just an index of the minutes. This has been invaluable in scanning through issues quickly of the CG and RDF 1.1 era meetings to find important resolutions.

What makes this work is code in https://github.com/json-ld/minutes/blob/master/scribe-tool/index.js#L194-L222 which rebuilds the index page over all minutes files.

We should consider doing something similar.