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

* Port to GitHub actions

* Fix

* Make docs terraform registry compatible

docs/data-sources/bitbucketserver_groups.md

@@ -0,0 +1,27 @@
+# Data Source: bitbucketserver_groups
+
+This data source allows you to retrieve a list of groups, optionally matching the supplied `filter`.
+
+## Example Usage
+
+```hcl
+data "bitbucketserver_groups" "all" { }
+```
+
+### Applying a Custom Filter
+
+Find any groups starting with `dev`.
+ 
+```hcl
+data "bitbucketserver_groups" "dev-groups" {
+  filter = "dev"
+}
+```
+
+## Argument Reference
+
+* `filter` - Optional. If specified only group names containing the supplied string will be returned.
+
+## Attribute Reference
+
+* `groups` - List of maps containing `name` key.