rendering md with layouts

testdata/index.md

@@ -0,0 +1,18 @@
++++
+layout = "layouts/post.html"
+title = "Pest Toast"
++++
+Test
+===
+
+This is a test. This is only a test.
+~~~rust
+fn main() {
+    println!("Here is some Rust")
+}
+~~~
+
+|This|is|
+|----|--|
+|a|table|
+