Rename "API" section to "Programming" to be more approachable

Author: RealOrangeOne

docs/.pages

@@ -1,5 +1,5 @@
 nav:
     - index.md
     - tutorials
-    - API: api
+    - rules
     - ...

docs/api/arduino.md docs/programming/arduino.mddocs/api/arduino.md renamed to docs/programming/arduino.md

@@ -1,11 +1,11 @@
----
-title: API
----
+# Programming
 
 Programming your robot is done in [Python](https://www.python.org/),
 specifically version 3.9.6. You can learn more about Python from their
 [docs](https://docs.python.org/3/), and our whirlwind tour.
 
+Each board has an API which allows its various functionality to be controlled.
+
 ## Setup
 
 The following two lines are required to complete initialisation of the
@@ -81,3 +81,5 @@ install some extra ones which may be of use:
 
 !!! tip
     If you would like an extra library installed, go and ask a volunteer to see if we can help.
+
+*[API]: Application Programming Interface