doc: Add more docs and links for KCL import (#4488)

* Add links in docs to KCL module documentation

* Add import statement test in import() stdlib doc comments

* Update doc test outputs

* Update doc outputs

src/wasm-lib/kcl/common.kcl

@@ -0,0 +1,20 @@
+// This file is used by the import docs.
+
+export fn width = () => {
+  return 10
+}
+
+export fn height = () => {
+  return 10
+}
+
+export fn buildSketch = (plane, offset) => {
+  w = width()
+  h = height()
+  return startSketchOn(plane)
+  |> startProfileAt(offset, %)
+  |> line([w, 0], %)
+  |> line([0, h], %)
+  |> line([-w, 0], %)
+  |> close(%)
+}