Clarify documentation for Geometry2D.line_intersects_line

[GrahameGW]

line_intersects_line has parameters from and dir to define each line that implies the intersecting lines are rays (rather infinite lines, which they actually are). As this caused me confusion, I wrote some clarifying examples and attempted to improve this description. It would also be a good idea to rename these parameters from from and dir to point and slope respectively to further eliminate this confusion, and even further amend this description to point users to a function that does check rays for intersection.

[Mickeon]

These lines are too long and will not display as nicely as you imagine. I would suggest putting the comment on a new line.

For this kind of example, what I have more often seen is "Variable is value", over "Returns value". The latter is completely fine, too, but it could be done only when not actually assigning the return value. It's a very opinionated suggestion, though.

Suggested change

	var intersect_right = Geometry2D.line_intersects_line(from_a, dir_a, from_b, Vector2(1, -1)) # returns Vector2(1, 0)
	var intersect_left = Geometry2D.line_intersects_line(from_a, dir_a, from_b, Vector2(-1, -1)) # returns Vector2(-1, 0)
	var intersect_none = Geometry2D.line_intersects_line(from_a, dir_a, from_b, Vector2.RIGHT) # returns null
	# intersect_right is Vector2(1, 0)
	var intersect_right = Geometry2D.line_intersects_line(from_a, dir_a, from_b, Vector2(1, -1))
	# intersect_left is Vector2(-1, 0)
	var intersect_left = Geometry2D.line_intersects_line(from_a, dir_a, from_b, Vector2(-1, -1))
	# intersect_none is null
	var intersect_none = Geometry2D.line_intersects_line(from_a, dir_a, from_b, Vector2.RIGHT)

[GrahameGW]

I went with the latter in the interests of further shortening the lines. I think it's more readable and it doesn't really do much for readability to assign the results and add an example comment

[GrahameGW]

These are good suggestions, thanks guys. I'll clean things up a bit and push changes. I was struggling w/ the pre-commit hooks so I've been focused on that but now I've got it working (at least locally) so I'll go back and review this stuff