docs: add compose preview screenshots to 5 imageless doc pages

Add image references to map-and-waypoints, settings-module-admin,
mqtt, tak, and units-and-locale using existing CST-generated screenshots.
Add 5 new semantic aliases for module config UI elements.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jamesarich

docs/assets/screenshots/map_controls_overlay.png

@@ -40,6 +40,8 @@ Node markers on the map indicate:
 
 The floating toolbar provides quick access to compass, layer switching, node filters, refresh, and location tracking. Tap the compass to reorient north-up, or tap the location button to center on your current position.
 
+![Map controls overlay](/assets/screenshots/map_controls_overlay.png)
+
 ## Waypoints
 
 Waypoints are shared geographic points of interest that all mesh members can see.

docs/assets/screenshots/nodes_environment_metrics.png

@@ -37,6 +37,8 @@ A gateway node with internet access (WiFi or Ethernet) publishes mesh messages t
 2. Enable the MQTT module.
 3. Configure the broker connection:
 
+![MQTT toggle switch](/assets/screenshots/settings_switch.png)
+
 | Setting | Description | Default |
 |---------|-------------|---------|
 | Server Address | MQTT broker hostname | mqtt.meshtastic.org |

docs/assets/screenshots/settings_appearance.png

@@ -15,6 +15,12 @@ Configure optional feature modules and perform device administration. Modules ex
 
 > 💡 **Tip:** You only need to enable the modules you actually use. Disabling unused modules reduces airtime, saves battery, and simplifies your configuration.
 
+Module settings use a card-based layout with toggle switches, dropdowns, text fields, and sliders:
+
+![Toggle switch](/assets/screenshots/settings_switch.png)
+
+![Dropdown selector](/assets/screenshots/settings_dropdown.png)
+
 ## Module Configuration
 
 ### MQTT Module