README.md: better usage instructions

[Nowaker]

No description provided.

[mbag]

hi @Nowaker I commented about adding note that the syntax in README is for terraform v0.13 or higher. Once that is added I'll merge the PR. I don't expect someone to be using terraform <=0.12 but just so that it's clear with which version the syntax used works.

[Nowaker]

Done!

[c33s]

@mbag why the drop of older terraform versions? the provider runs quite fine with 0.11. and everything over 0.11 has a security impact for us. see hashicorp/terraform#26141

edit: oh i think i missed that you only wrote about syntax. i feared you merge something which actually break something on older terraform versions. and yes there are still old version out there :)

[mbag]

@c33s I'm actually not sure if older versions will be able to fetch newer releases directly from the Registry. I think that older versions are fetching providers from different URLs than registry.terraform.io.

[c33s]

@mbag it works, i manually downloaded the powerdns provider yesterday (updated from 1.3 to 1.4 with terraform 0.11) works like charm. having only the problems where i opened issues for. so 1.4 is 0.11 compatible

[mbag]

@c33s manual download and placing provider in the search path of the terraform should work of course, that's why I wrote directly from Registry. Because Hashicorp has discontinued old way of releasing and only support publishing providers on the Registry.