more esoteric with the docs; center all by default; genericity without subject doesnt compile lol

layout/README.md

@@ -2,20 +2,24 @@
 
 this crate exposes several layout operators
 which work entirely in unsigned coordinates
-and are generic over `tek_engine::Engine`.
+and are generic over `tek_engine::Engine`
+and `tek_engine::Content`. chiefly, they
+are not dependent on rendering framework.
 
-* `Fill` makes the content's dimension equal to the container's.
-* `Fixed` assigns a fixed dimension to its content.
-* `Shrink` reduces the dimension of the content
-* `Expand` increases the dimension of the content
-* `Min` enforces minimum dimension for the content
-* `Max` enforces maximum dimension for the content
-* `Push` moves the content in the positive direction
-* `Pull` moves the content in the negative direction
-* `Margin` grows each dimension from both ends
-* `Padding` shrinks each dimension from both ends
-* `Align` pins the content along an axis of the container
-* `When` renders a content conditionally
-* `Either` alternates between two contents
-* `Map` transforms each content
-* `Reduce` transforms all contents into one
+* `Fill` is to make the content's dimension equal to the container's.
+* `Fixed` is to assign a fixed dimension to its content.
+* `Shrink`/`Expand` are to change the dimension of the content
+* `Min`/`Max` are to constrain the dimension of the content
+* `Push`/`Pull` are to move the content along the axis
+* `Margin`/`Padding` are to change the dimension proportionally
+* `Align` is to pin the content along the axis of the container
+* `When` is to render content conditionally
+* `Either` is to alternates between contents
+* `Map` is to transform each content
+* `Reduce` is to transform all contents into one
+* and, finally, `Bsp` is to put 2 where there was 1.
+
+**todo.** and then you're like,
+"but why are they generic over E in the first place
+and not, say, over E::Unit? that might even free up
+some space to implement for non-uint cosmologies...