Update installation guide for terraform 0.13+ (Snowflake-Labs#301)

README.md

@@ -26,6 +26,22 @@ It runs a script generated by [godownloader](https://github.com/goreleaser/godow
 
 You can also just download a binary from our [releases](https://github.com/chanzuckerberg/terraform-provider-snowflake/releases) and follow the [Terraform directions for installing 3rd party plugins](https://www.terraform.io/docs/configuration/providers.html#third-party-plugins).
 
+### For Terraform v0.13+ users
+You can use [Explicit Provider Source Locations](https://www.terraform.io/upgrade-guides/0-13.html#explicit-provider-source-locations).
+
+The following maybe work well.
+
+```terraform
+terraform {
+  required_providers {
+    snowflake = {
+      source = "chanzuckerberg/snowflake"
+      version = "0.18.1"
+    }
+  }
+}
+```
+
 TODO fogg config
 
 ## Usage