doc: Add README to explain the project

In order to explain the project, a README is added.

Author: QuentinCG

README.md

@@ -0,0 +1,52 @@
+# I2C Temperature Sensor (LM75A) Library for Arduino
+
+## What is it?
+
+This library (with example) is designed to be integrated in projects using LM75A sensors to get temperature.
+
+<img src="device.png" width="300">
+
+
+## How to install
+
+1) Download <a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/releases/download/1.0.0/LM75A_v1_0_0.zip">latest release</a>
+
+2) On your Arduino IDE, click "Sketch" menu and then "Include Library > Add .ZIP Libraries"
+
+3) You can now use the library for your project or launch an example ("File > Examples")
+
+
+## How to connect the sensor to your Arduino
+
+LM75A sensor | Arduino
+-------- | --------
+VCC      | 3.3V
+GND      | GND
+SDA      | A4 (SDA)
+SCL      | A5 (SCL)
+A0      | GND (or VCC to increase I2C address of 1)
+A1      | GND (or VCC to increase I2C address of 2)
+A2      | GND (or VCC to increase I2C address of 4)
+OS      | None
+
+
+<img src="schematics.png" width="400">
+
+
+## Examples
+
+One example is provided with this library:
+
+### Show temperature in degrees and fahrenheit every second
+
+<a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/blob/master/LM75A/examples/LM75A_ShowTemperature/LM75A_ShowTemperature.ino">Link to source code</a>
+
+
+## License
+
+This project is under MIT license. This means you can use it as you want (just don't delete the library header).
+
+
+## Contribute
+
+If you want to add more examples or improve the library, just create a pull request with proper commit message and right wrapping.