Add tutorial on coordinates

docs/coordinates.rst

+Coordinates
+===========
+
+The library uses 2 types of coordinate classes. One for integers and one for 
+floats, these are called :class:`library.Point2DI` and 
+:class:`library.Point2D`.
+
+Point2DI
+--------
+
+
+.. class:: library.Point2DI
+
+   These points are used for defining the location of tiles, which are used when 
+   placing buildings in Starcraft. 
+
+   Not many operators are defined for this class, only equality, inequality and
+   converting to strings are defined.
+
+
+Point2D
+-------
+
+.. class:: library.Point2D
+
+   Instances of this class is used to represent the location of Units and
+   support many operations for general purpose calculation.
+
+Example
+~~~~~~~
+
+.. code:: python
+
+   from library import Point2D, Point2DI
+   
+   # Creating two points
+
+   p1 = Point2D()  # Defaults to (0, 0)
+   p2 = Point2D(1, 2)
+   
+   # Adding two points
+   p1 += p2
+
+   # Multiplying a point with a scalar
+   p2 *= 3
+   
+   # Creating a new point, defined as the sum of p1 and p2
+   p3 = p1 + p2
+   
+   print(p1)
+   print(p2)
+   print(p3)
+   
+   # The same works for Point2DI
+   pi1 = Point2DI(1, 2)
+   pi2 = Point2DI(1, 2)
+   
+   # However, we can only compare them. There are no operators for addition,
+   # subtraction or multiplication.
+   print(pi1 == pi2)  # prints: True
+
+
+It is also possible to define custom operators for these points, as shown
+below:
+
+.. code:: python
+
+   from math import sqrt
+   from library import Point2D
+
+   p1 = Point2D(3, 4)
+   p2 = Point2D(1, 2)
+   
+   # Defining a custom @ operator, like this
+   Point2D.__matmul__ = lambda self, other: self.x * other.x + self.y * other.y
+
+   print(p1 @ p2)  # prints: 11.0
+
+   # Or maybe a distance operator:
+   Point2D.distance = lambda self, other: sqrt((self.x - other.x)**2 + (self.y - other.y)**2)
+
+   print(p1.distance(p2))  # prints: 2.8284...
+

docs/index.rst

@@ -14,6 +14,7 @@ This is a Python library based on the CommandCenter bot for implementing bots fo
    idabot
    unit
    types
+   coordinates
    constants
    
 Short overview