Start to rework some of our kcl docs (#3222)

* Start to rework some of our kcl docs

Signed-off-by: Paul R. Tagliamonte <paul@zoo.dev>

src/wasm-lib/kcl/src/std/shell.rs

@@ -31,7 +31,9 @@ pub async fn shell(args: Args) -> Result<MemoryItem, KclError> {
     Ok(MemoryItem::ExtrudeGroup(extrude_group))
 }
 
-/// Shell a solid.
+/// Remove volume from a 3-dimensional shape such that a wall of the
+/// provided thickness remains, taking volume starting at the provided
+/// face, leaving it open in that direction.
 ///
 /// ```no_run
 /// const firstSketch = startSketchOn('XY')