Create Player Controller (#4)

* add player scene

* add some logic to control player velocity

* add debug scene and reset main scene

* add sun and env to debug scene; fix normalization of movement

* add kenney WIP assets for debug

* fix movement further and add jump

* add mouse camera control

* add sprinting

* add crouching

* use constants for height

* try to improve crouching by checking to see if there is a collision above before un-crouching

* update README about line width

* move test cube in front of playercontroller

README.md

@@ -66,3 +66,24 @@ Bad:
 ```gdscript
 const S: 300.0
 ```
+
+Keep single code line length up to 80 characters long. (Notice the first vertical line
+in the text editor.)
+
+This keeps code easier to read because it isn't stretching all the way across the screen.
+
+Good:
+
+```gdscript
+@onready var head_collision_shape: CollisionShape3D \
+	= $HeadCollider/HeadCollisionShape
+```
+
+Bad:
+	
+```gdscript
+@onready var head_collision_shape: CollisionShape3D = $HeadCollider/HeadCollisionShape
+```
+
+Notice the `\` in the above "good" example. That tells Godot to continue the expression
+on the next line.