Added an option to rotate the numbers shown on NumberLine

[abdallahsoliman00]

Motivation

The numbers on the y-axis of Axes are horizontal:

There is no feature to make them vertical.

Proposed changes

To make them vertical, the NumberLine class (the mobject used to create the axes) was edited where a new argument number_orientation was introduced the the __init__.

The variable number_orientation takes in the rotation in radians.

The y_axis_config argument within Axes can now include the number orientation value.

Test

Code:

class Test(Scene):
        ax = Axes(
            x_range=(0,x_max,1),
            y_range=(0,x_max+1,1),
            height=6,
            width=6,
            x_axis_config={'include_numbers': True},
            y_axis_config={
                'include_numbers': True,
                'line_to_number_direction': UP,
                'number_orientation' : -PI/2
            }
        )
        self.add(ax)

Result: