docs(configuration): text sensors are sensor sub-keys, not a platform (#52)

The Text Sensors section showed a `text_sensor: - platform: tigo_monitor`
block, which cannot validate — there is no text_sensor.py in the component,
and ESPHome fails with "Platform not found: 'text_sensor.tigo_monitor'".
barcode/firmware_version/device_info are sub-keys of a `sensor:` entry; the
component builds the text entities itself via text_sensor.new_text_sensor.

Wrong since 2026-07-23. Verified both forms against `esphome config`: the
documented one fails, the corrected one validates and mixes with the numeric
sub-keys.

Author: RAR

site/src/content/docs/guides/configuration.md

@@ -386,8 +386,13 @@ cards, each grouping the entities for its panels.
 
 ### Text Sensors
 
+A panel's barcode, firmware version and device info are text entities, but they
+are declared like every other measurement — as sub-keys of a **`sensor:`** entry.
+There is no `text_sensor:` platform for `tigo_monitor`; the component creates the
+text entities itself.
+
 ```yaml
-text_sensor:
+sensor:
   - platform: tigo_monitor
     tigo_monitor_id: tigo_hub
     address: "1234"
@@ -397,6 +402,19 @@ text_sensor:
     device_info: {}
 ```
 
+They mix freely with the numeric sub-keys, so one entry per panel covers both:
+
+```yaml
+sensor:
+  - platform: tigo_monitor
+    tigo_monitor_id: tigo_hub
+    address: "1234"
+    name: "Panel 1"
+    power: {}
+    temperature: {}
+    barcode: {}
+```
+
 ### Binary Sensors
 
 ```yaml