Remove unmonitored contact form

[patcon]

We prob shouldn't be keeping this up:
http://g0v.network/join/

People are still signing up for it (e.g., only 8 in past year though):
🔒 signups: https://airtable.com/tblwSK7VGUUqb6Txc/viwfA2KulSMppaB47?blocks=hide

Potential Options:

1. create wide-access mailing list for people interested in more international g0v efforts, and alert there
2. just remove it
3. point people to g0v.tw slack
4. seek advice from g0v.tw community members at https://beta.hackfoldr.org/g0v-hackath43n
5. something else? ...

EDIT: daily unique visitors this past month: 50-250

cc: @devinbalkind