add preamble describing what a guide is about

docs/administration-guide.md

 #Administration Guide
+
+> **This guide will teach you:**
+> How to connect Metabase to databases in your organization
+> How to set up email 
+> How to manage user accounts
+> How to backup Metabase application data
+> How to deal with common problems
+
 ---
 In charge of managing Metabase for your organization?  Then, you're in the right spot.  This guide covers setting up database connections, configuring email settings, and managing user accounts.
 

docs/developers-guide.md

+
+> **This guide will teach you:**
+> How to compile your own copy of Metabase
+> How to set up a development environment
+> How to run the Metabase Server
+> How to contribute back to the Metabase project
+
+
 [![Circle CI](https://circleci.com/gh/metabase/metabase-init.svg?style=svg&circle-token=3ccf0aa841028af027f2ac9e8df17ce603e90ef9)](https://circleci.com/gh/metabase/metabase-init)
 
 ## Install Prerequisites

docs/getting-started.md

 #Welcome to Metabase
 Metabase lets you ask questions about your data, drill into specific records, and dashboards to help keep you organized.  
 
+> **This guide will teach you:**
+>
+> How to install Metabase on your laptop or server
+> How to connect Metabase to a database
+> How to ask your first questions
+
+
+
 ##Step 1: Installing Metabase
 Metabase uses Java to operate, so you'll need at least version 1.6 or later.  Not sure what version of Java you're using?  No problem.  Here's how to check: 
 

docs/installation-guide.md

+
+> **This guide will teach you:**
+> How to install Metabase 
+> Where to place the data that Metabse generates
+> How to run Metabase in production uses
+> Common issues that come up installing Metabase
+
 # Overview
 
 The Metabase server can be run anywhere that you can run a Java jar. On installation it will have three main portions. First off is the Jar containing the server code. The most recent stable version can be download from [Metabase Downloads](http://wwww.metabase.com/downloads). Next there will need to be a place where Metabase can store persistent data, or its Application Database. Once the server is up and running with a place to store application data, you can connect to one or more Databases. 

docs/metadata-guide.md

+
+> **This guide will teach you:**
+> What kinds of metadata Metabase stored and uses
+> How Metabase scans your database
+> How to improve the data model by adding your own knowledge to the auto-generated model
+
 # Overview
 
 Metabase allows you to optionally annotation the data in your database or datawarehouse. These annotations provide metabase with an understanding of what the data actually means and allows it to more intelligently process and display it for you. We currently allow you to annotate tables and columns. 

docs/users-guide.md

 #User Guide
 
+> **This guide will teach you:**
+>
+> What Metabase does
+> The basics of database terminology
+> What Metabase questions are made up of
+> How to ask basic questions
+> How to visualize the answers to questions
+> How to share answers with others through dashboards
+> Tips on creating useful dashboards
+
+
 ## Overview
 ---
 ### What is Metabase?