Include all postmeta data under post['postmeta']

[Cabalist]

Hey there,

Thanks for this project! I've been using this a lot to pull data out of wordpress exports. I noticed however that the majority of the post meta info was being thrown away. I added it in (and moved an import statement).

I've got some other fixes/improvements I'd like to PR if you are open to them. I really appreciate your work on this. :)

[marteinn]

Hi @Cabalist and thanks for the PR! Will review this and try to get back in a day or two. To be continued.

[Cabalist]

Awesome! Thanks! It evolved a little past the original PR with all the typing and some the python versions. We've been using it successfully in that time. 😄

[daar]

Hi, could you please merge this PR?

[todschmidt]

Nice PR. I just posted a super abbreviated version that mirrors one of your changes and felt obligied to point out that PRs should be as small as possible and not combine multiple features when possible.

That said @marteinn, worth taking a look. Or at mine :-)