Update library installation instructions

README.md

@@ -20,12 +20,16 @@ Wire the SDA and SCL pins of the Si5351 to the corresponding pins on the Arduino
 
 Connect a 25 MHz or 27 MHz crystal with a load capacitance of 6, 8, or 10 pF to the Si5351 XA and XB pins. Locate the crystal as close to the Si5351 as possible and keep the traces as short as possible. Please use a SMT crystal. A crystal with leads will have too much stray capacitance.
 
-Example
--------
-Include the Si5351Arduino library into your instance of the Arduino IDE. Download a ZIP file of the library from the GitHub repository by using the "Download ZIP" button at the right of the main repository page. Extract the ZIP file, then rename the unzipped folder as "Si5351". Finally, open the Arduino IDE, select menu Sketch > Import Library... > Add Library..., and select the renamed folder that you just downloaded. Restart the IDE and you should have access to the new library.
+Library Installation
+--------------------
+The best way to install the library is via the Arduino Library Manager, which is available if you are using Arduino IDE version 1.6.2 or greater. To install it this way, simply go to the menu Sketch > Include Library > Manage Libraries..., and then in the search box at the upper-right, type "Etherkit Si5351". Click on the entry in the list below, then click on the provided "Install" button. By installing the library this way, you will always have notifications of future library updates, and can easily switch between library versions.
+
+If you need to or would like to install the library in the old way, then you can download a copy of the library in a ZIP file. Download a ZIP file of the library from the GitHub repository by using the "Download ZIP" button at the right of the main repository page. Extract the ZIP file, then rename the unzipped folder as "Si5351". Finally, open the Arduino IDE, select menu Sketch > Import Library... > Add Library..., and select the renamed folder that you just downloaded. Restart the IDE and you should have access to the new library.
 
 (Yes, the Arduino IDE can import a ZIP file, but it doesn't like filenames with characters such as dashes, as GitHub does when it appends the branch name with a dash. Perhaps there's an elegant way around this, we'll see.)
 
+Example
+-------
 There is a simple example that is placed in your examples menu under Si5351Arduino. Open this to see how to initialize the Si5351 and set a couple of the outputs to different frequencies. The commentary below will analyze the sample sketch.
 
 Before you do anything with the Si5351, you will need to include the "si5351.h" and "Wire.h" header files and instantiate the Si5351 class.