Facebook and Twitter cards do not always find the correct image

[lmergner]

Imported from TaskWarrior

Facebook and Twitter support the concept of "cards" or rich metadata found in the tag to add images and descriptions to shared links. This is important since it affects how CR looks on social media.

Right now, twitter (especially) is not finding the correct image. Did I include the wrong link in the twitter metadata tags (in layout.html) or is Twitter defaulting to a different image because the metadata is wrong. Or, perhaps, does Twitter require us to manually create a card for each page (that would be weird, but it's documentation isn't completely clear).