Remove date (we don't add those)

Blaisorblade · Blaisorblade · commit 90b1d6721fb5 · 2018-05-11T15:24:47.000+02:00
diff --git a/docs/docs/reference/simple-smp.md b/docs/docs/reference/simple-smp.md
@@ -3,8 +3,6 @@ layout: doc-page
 title: "The Meta-theory of Symmetric Meta-programming"
 ---
 
-23.12.2017
-
 This note presents a simplified variant of
 [principled meta-programming](./principled-meta-programming.md)
 and sketches its soundness proof. The variant treats only dialogues
