including from rel=alternate

* mf2+html
* mf2+json
* feed+json
* xml
* instagram/facebook/github/xkcd

returns a new property `post-type` next to `type`

closes #25

closes #73

parse from both link tags and the u-redirect-uri property

adds script to refresh the downloaded instagram data for the tests as well

instagram seems to have rolled out the `graphql` key everywhere now

main difference is the deprecated rel handling

closes #62

also expands parsing to be able to handle twitter JSON from the streaming API which is subtly different from the HTTP API.

closes #61

tells the editor to save data files with crlf needed for parsing the test http responses

closes #13

closes #51

closes #57

for #57

fix for #53

* adds test of instagram-atom feed with individual authors per item
* dedupes atom/rss title if it's a prefix of the content

if an item has multiple URL values, return the one that is on the same domain

Treats `https://example.com` and `https://example.com/` as equivalent when comparing URLs. Closes #33

closes #32