docs: Add type field documentation to runtime policies (#101)

Author: tembleking

website/docs/r/sysdig_secure_policy.md

@@ -51,6 +51,8 @@ resource "sysdig_secure_policy" "write_apt_database" {
 
 * `enabled` - (Optional) Will secure process with this rule?. By default this is true.
 
+* `type` - (Optional) Specifies the type of the runtime policy. Must be one of: `falco`, `list_matching`, `k8s_audit`, `aws_cloudtrail`. By default it is `falco`.
+
 - - -
 
 ### Scope selection