Add OpenGraph data

[MineRobber9000]

This allows for rich embeds. As this is primarily a backend change, nothing should truly change in the articles department (merge conflicts should be easily fixed).

• [X] Add OGP generation to templates/article.html
  • [X] Add configuration to change the absolute path of the published neowiki build
  • [X] Get an image to use
• [X] Fix any OGP generation problems we have regarding the main page (templates/mainpage.html)
  • [X] Add override section to OGP tags
  • [X] Figure out OGP values for main page

(Don't mind the first commit, forgot I wasn't in master.)

[MineRobber9000]

The only required change now is to get an image to use for the wiki embeds. Anyone have any ideas how to get one? Should we bug Capy?

[dotcomboom]

Dropping these here for future reference. Globe graphic shamelessly lifted from Wikimedia Commons (public domain).

and this is le fancy one!

[MineRobber9000]

The logo is the blocking change. When I get home I'll add the logo (I think I'll go with le fancy one) and then this can be merged. The other PRs can then be merged.

(also, I can use the non-fancy one on the button design (it's able to be represented in a small space))

[MineRobber9000]

I'm going to merge this now that it's done.