README.md: Fix MD025 warnings
The following warnings are generated by using markdownlint analysis:
```
MD025/single-title/single-h1 Multiple top-level headings in the same document [Context: "# Sensor Type Documentation"]
```
Refer to markdown-lint [1] to fix MD025
[1]: https://github.com/updownpress/markdown-lint/blob/master/rules/025-single-h1.md
Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Change-Id: Ibb6361abd1da5afe9c0900242bc58546b4479a41
diff --git a/README.md b/README.md
index 3a3b80e..1920d6e 100644
--- a/README.md
+++ b/README.md
@@ -69,9 +69,9 @@
- [ExternalSensor](https://github.com/openbmc/docs/blob/master/designs/external-sensor.md)
virtual sensor
-# Sensor Type Documentation
+## Sensor Type Documentation
-## ADC Sensors
+### ADC Sensors
ADC sensors are sensors based on an Analog to Digital Converter. They are read
via the Linux kernel Industrial I/O subsystem (IIO).