docs: Adding verification tools placeholders.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>
diff --git a/docs/verification/drc.rst b/docs/verification/drc.rst
new file mode 100644
index 0000000..10f9b4a
--- /dev/null
+++ b/docs/verification/drc.rst
@@ -0,0 +1,8 @@
+Design Rule Verification
+========================
+
+.. toctree::
+
+    With Mentor Calibre <drc/calibre>
+    With Magic <drc/magic>
+    With KLayout <drc/klayout>