docs: update docker info (#322)

Author: langchain-infra

versioned_docs/version-2.0/self_hosting/installation/docker.mdx

@@ -77,7 +77,7 @@ docker-compose up -d
 
 1. Visit the exposed port of the `cli-langchain-frontend-1` container on your browser
 
-   The Langsmith UI should be visible/operational
+   The Langsmith UI should be visible/operational at `http://localhost:1980`
 
    ![.langsmith_ui.png](../static/langsmith_ui.png)