Port to GitHub actions & publish to Terraform registry (#39)

* Port to GitHub actions

* Fix

* Make docs terraform registry compatible

docs/data-sources/bitbucketserver_group_users.md

@@ -0,0 +1,31 @@
+# Data Source: bitbucketserver_group_users
+
+Retrieve a list of users for a specific group.
+
+## Example Usage
+
+```hcl
+data "bitbucketserver_group_users" "stash-users" {
+  group = "stash-users"
+}
+```
+
+### Applying a Custom Filter
+
+Find any users starting with `malcolm`.
+ 
+```hcl
+data "bitbucketserver_group_users" "malcolms" {
+  group  = "stash-users"
+  filter = "malcolm"
+}
+```
+
+## Argument Reference
+
+* `group` - Required. Group to find the users for.
+* `filter` - Optional. If specified only users matching name/email for the supplied string will be returned.
+
+## Attribute Reference
+
+* `users` - List of maps containing `name`, `email_address`, `display_name` and `active` keys.