build: readme that marks schematics sources as internal (angular#14596)

devversion · josephperrott · commit fd229d4992c7 · 2019-01-14T15:13:50.000-08:00
In order to make clear that the sources/exports of the `cdk/schematics` directory are only intended for internal use, we should add a readme that makes this clear.
diff --git a/src/cdk/schematics/README.md b/src/cdk/schematics/README.md
@@ -0,0 +1,4 @@
+## CDK schematics
+
+The sources of this directory are only used internally and should not be considered
+as part of the public API
