add link for description of HardwareSerial

tenbaht · tenbaht · commit 88e3d0d3db09 · 2019-09-26T12:58:08.000+02:00
diff --git a/docs/index.md b/docs/index.md
@@ -53,7 +53,7 @@ details.
 
 * [SPI](api/SPI.md): Real hardware-SPI up to 10MHz.
 * [I2C](api/I2C.md): Port of the I2C master library by Wayne Truchsess
-* HardwareSerial: The standard serial interface.
+* [HardwareSerial](api/HardwareSerial.md): The standard serial interface.
 
 #### Displays
 
