Patreon API updates

* Create patreon.jq

* Create check_pr.jq

* Rename check_pr.jq to .autogen/check_pr.jq

* Create next_url.jq

* Update autogen.sh

* Rename autogen.sh to update_readme_patreon.sh

refs: https://github.com/syuilo/misskey/commit/8b98c08a81be1bb6a9c43d9cd82fe660fb09bc94#commitcomment-30911933

refs: https://github.com/syuilo/misskey/pull/2391#issuecomment-414915763