docs: Change Container to container, based on PR feedback

Author: nginx-seanmoloney

content/agent/how-to/run-agent-container.md

@@ -59,7 +59,7 @@ Replace the placeholder values:
 - `<your-data-plane-key-here>`: Your Data Plane access token.
 
 
-3. Run the Container
+3. Run the container
 
 Run the NGINX Agent container with the configuration file mounted.