Add book.toml with title to unstable-book doc

Bastian Gruber · Bastian Gruber · commit aea5bf55f0b4 · 2019-03-30T19:46:43.000+01:00
diff --git a/src/doc/unstable-book/book.toml b/src/doc/unstable-book/book.toml
@@ -0,0 +1,2 @@
+[book]
+title = "The Rust Unstable Book"
