update preamble syntax

docs/api.md

@@ -1,8 +1,9 @@
-target: reference/api
-template: reference
-title: Compiler API
-short_name: api
---
+{
+  target: "reference/api"
+  template: "reference"
+  title: "Compiler API"
+  short_name: "api"
+}
 
 # MoonScript Compiler API
 

docs/command_line.md

@@ -1,8 +1,9 @@
-target: reference/command_line
-template: reference
-title: Command Line Tools
-short_name: command_line
---
+{
+  target: "reference/command_line"
+  template: "reference"
+  title: "Command Line Tools"
+  short_name: "command_line"
+}
 
 # Command Line Tools
 

docs/reference.md

@@ -1,8 +1,9 @@
-target: reference/index
-template: reference
-title: Language Guide
-short_name: lang
---
+{
+  target: "reference/index"
+  template: "reference"
+  title: "Language Guide"
+  short_name: "lang"
+}
 
 MoonScript is a programming language that compiles to
 [Lua](http://www.lua.org). This guide expects the reader to have basic

docs/standard_lib.md

@@ -1,8 +1,9 @@
-target: reference/standard_lib
-template: reference
-title: Standard Library
-short_name: stdlib
---
+{
+  target: "reference/standard_lib"
+  template: "reference"
+  title: "Standard Library"
+  short_name: "stdlib"
+}
 
 The MoonScript installation comes with a small kernel of functions that can be
 used to perform various common things.