Quick export of data viz to image/PDF

[ngm]

We would like to have export options of the data visualisations, at least to image and PDF formats.

Two main use cases:

• When we at Restart HQ are producing and sending stats (i.e. the data viz) to people (such as funders of events), we currently take screenshots of the Impact and Details tabs off the host/admin dashboard.
• Hosts would like to have a simple way to print off hard copies of their stats to pin up in physical locations - as a way of motivating the local group (this was mentioned by Sophia).

[ngm]

Some issues to consider as mentioned by @IronRunes:

• to potentially reduce complexity, can we provide a ranking of which stats we would be most keen to export? (I will run this by Kathryn and Sophia)
• if we export to PDF, how do we deal with possibility of the viz splitting across two pages?
• there is interactivity on some of the stats from the dashboard (e.g. selecting which year it is for) - that would be difficult or perhaps not possible at all to incorporate in an export