Update README and CI pipeline

Author: dorranh

.github/workflows/ci.yaml

@@ -15,4 +15,4 @@ jobs:
     - name: Install Arduino CLI
       uses: arduino/setup-arduino-cli@v1.1.1
     - name: Build sketch
-      run: make build
+      run: make all

README.md

@@ -12,8 +12,10 @@ This sketch is currently designed to work with the following Arduino boards:
 To build this sketch on the command line, you will need the following tools installed. Please see their respective installation guides for instructions on how to install them.
 
   1. [make](https://www.gnu.org/software/make/) - Installation of `make` is OS-dependent. The provided link includes a download page for installing make on OSX and Linux. (See [here](https://stackoverflow.com/questions/32127524/how-to-install-and-use-make-in-windows) for more info on installing on Windows).
+  1. [python3](https://www.python.org/downloads/) - Used internally by some of the Arduino libraries
   1. [arduino_cli](https://arduino.github.io/arduino-cli/latest/)
 
+
 With those installed you can build the sketch with:
 
 ```shell