added upgrade instructions

src_docs/source/installation.rst

@@ -3,7 +3,7 @@
 Installation 
 ------------
 
-You have these 3 options for flashing this firmware:
+You have these 3 options for flashing this firmware. 
 
 * Brewflasher via USB serial
 * Esptool via USB serial
@@ -67,6 +67,32 @@ an option for updating firmware. The option is under the maintence meny.
 
 Select the esp8266 version of the firmware called firmware.bin and press upload. 
 
+Updating firmware 
+=================
+
+You can use the above options for updating the firmware as well. But if you want to do updates without connecting the USB cable these 
+are your options.
+
+OTA Option
+**********
+
+You can use the OTA option by adding this URL to your configuration and when the device starts up in configuration mode it 
+will check for a new version and if it finds a newer version it will do an update.
+
+``https://mp-se.github.io/gravitymon/release/``
+
+Manual update
+*************
+
+When the device in is configuration mode you can manually update with a new firmware. Just open this URL in the web 
+browser and select the firmware.bin file that corresponds to the version you want to flash. 
+
+``http://<device_name>/firmware.htm``
+
+
+
+.. _serial_monitoring:
+
 Serial Monitoring
 =================