docs: Clarify coordinate spaces

site/docs/02-fundamentals/02-conventions.mdx

@@ -22,7 +22,13 @@ There are a few things that Excalibur does that are good to know before you star
 5. Actor z-index's follow the browser way of doing things.
    * Things with larger positive numbers are on top of lower numbers.
 
-6. Things are in "world" space unless specified with a `local` prefix or added as a child actor. World space is the pixel position where Entities and Actors live by default.
+6. Coordinate Spaces
+   * World space is the pixel position where Entities and Actors live by default.
+   * Screen space is the pixels on the canvas element viewport according to the browser.
+   * Page space is pixel offset from the top left of browser window
+   * Local space is relative to a parent Entity or Actor
+
+6. Things are in "world" space unless specified with a `local` prefix or added as a child actor.
 
 7. Bounds are always an axis aligned bounding box, meaning a non-rotated box.