add release metadata

.ldrelease/config.yml

@@ -0,0 +1,8 @@
+template:
+  name: go
+  env:
+    LD_RELEASE_GO_IMPORT_PATH: github.com/launchdarkly/go-ntlmssp
+
+publications:
+  - url: https://godoc.org/github.com/launchdarkly/go-ntlmssp
+    description: documentation