Add link to ref docs in Dev server README

Author: tvarney13

internal/dev_server/README.md

@@ -2,3 +2,6 @@
 The dev server is a go server that ldcli can run. It provides a local-only version of all the APIs that support LaunchDarkly SDKs. You can use it to serve flags to local and ephemeral environments. It copies flag _values_ for a project from a source environment and serves those. There are also APIs that let you override those values so that you can enable a feature just in your dev environment, e.g.
 
 The build of the dev server is incorporated into the ldcli build itself. The UI provided by the dev server has a [manual build](./ui/README.md).
+
+## Reference Docs
+For assistance starting with or running dev-server, refer to the [reference docs](https://launchdarkly.com/docs/guides/flags/ldcli-dev-server).