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

* Port to GitHub actions

* Fix

* Make docs terraform registry compatible

docs/resources/bitbucketserver_plugin_config.md

@@ -0,0 +1,25 @@
+# Resource: bitbucketserver_plugin_config
+
+Configure plugins.
+
+## Example Usage
+
+```hcl
+resource "bitbucketserver_plugin_config" "mypluginconfig" {
+  config_endpoint = "/rest/1.0/myplugin/config"
+  values          = "{"\key\": \"value\"}"
+}
+```
+
+## Argument Reference
+
+* `config_endpoint` - Required. Path to the configuration endpoint. Relative to the bitbucket server url configured in the provider.
+* `values` - Required. Plugin configuration in JSON format.
+
+## Import
+
+Import a plugin config reference via the key:
+
+```
+terraform import bitbucketserver_plugin_config.mypluginkey my-plugin-key
+```