docs: update README for agent URL and auth token instructions

Clarified instructions for setting agent URL and auth token in README.

Author: tom-draper

dashboard/README.md

@@ -26,7 +26,7 @@ If your NGINX log path is different from the default `/var/log/nginx`, set the c
 NGINX_ANALYTICS_ACCESS_PATH=/path/to/access/logs
 ```
 
-If you are using the [agent](../agent/README.md), set the agent URL and the optional auth token.
+If you are using the [agent](../agent/README.md), set the agent URL and the optional auth token instead.
 
 ```env
 NGINX_SERVER_URL=https://your-agent.com
@@ -41,7 +41,7 @@ Pull the prebuilt image from GitHub Container Registry:
 docker pull ghcr.io/tom-draper/nginx-analytics-dashboard:latest
 ```
 
-**Local mode** - read log files directly (mount them as a volume):
+Read log files directly (mount them as a volume):
 
 ```bash
 docker run -d \
@@ -51,7 +51,7 @@ docker run -d \
   ghcr.io/tom-draper/nginx-analytics-dashboard:latest
 ```
 
-**Remote mode** - connect to a running [agent](../agent/README.md):
+If you are using the [agent](../agent/README.md), set the agent URL and the optional auth token instead.
 
 ```bash
 docker run -d \