Add examples and HC-SR04 distance sensor library

Author: Erriez

.gitmodules

@@ -73,3 +73,6 @@
 [submodule "libraries/ErriezArduinoExamples"]
 	path = libraries/ErriezArduinoExamples
 	url = https://github.com/Erriez/ErriezArduinoExamples
+[submodule "libraries/ErriezHCSR04"]
+	path = libraries/ErriezHCSR04
+	url = https://github.com/Erriez/ErriezHCSR04

README.md

@@ -1,6 +1,7 @@
-# Erriez Arduino libraries and sketches
+# Erriez Arduino libraries and examples
+
+Erriez Arduino libraries and sketches contains examples and libraries for Arduino, tested on a various amount of hardware.
 
-Erriez Arduino libraries and sketches contains examples and optimized libraries for Arduino, tested on a various amount of hardware.
 
 ## Installation
 
@@ -16,6 +17,12 @@ git submodule update --recursive
 Move the libraries/* to your Arduino/libraries/ directory
 ```
 
+
+### [Arduino Examples](https://github.com/Erriez/ErriezArduinoExamples) [![Build Status](https://travis-ci.org/Erriez/ErriezArduinoExamples.svg?branch=master)](https://travis-ci.org/Erriez/ErriezArduinoExamples)
+
+Arduino examples and projects for several boards.
+
+
 ### [MH-Z19B CO2 Sensor](https://github.com/Erriez/ErriezMHZ19B) [![Build Status](https://travis-ci.org/Erriez/ErriezMHZ19B.svg?branch=master)](https://travis-ci.org/Erriez/ErriezMHZ19B)
 
 MH-Z19B CO2 sensor library for Arduino with a small footprint. Hardware and software serial supported.
@@ -58,6 +65,11 @@ I2C high-precision light sensor.
 [![BH1750](https://raw.githubusercontent.com/Erriez/ErriezBH1750/master/extras/BH1750.png)](https://github.com/Erriez/ErriezBH1750)
 
 
+### [HC-SR04](https://github.com/Erriez/ErriezHCSR04) [![Build Status](https://travis-ci.org/Erriez/ErriezHCSR04.svg?branch=master)](https://travis-ci.org/Erriez/ErriezHCSR04)
+
+HC-SR04 Ultrasonic Distance sensor. Measurement range: 2..2000cm +/-1cm.
+
+
 ### [CRC32](https://github.com/Erriez/ErriezCRC32)  [![Build Status](https://travis-ci.org/Erriez/ErriezCRC32.svg?branch=master)](https://travis-ci.org/Erriez/ErriezCRC32)
 
 Target independent, flash and RAM size optimized CRC32 library for Arduino without CRC tables.