Add quickstart example (#1483)

* Add quickstart example

* Add example dependencies

* Clean up title

* Clean up README footer

README.md

@@ -1,6 +1,4 @@
-## Learn more: http://www.yesodweb.com/book/persistent
-
-[![Join the chat at https://gitter.im/yesodweb/persistent](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/yesodweb/persistent?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Build Status](https://travis-ci.org/yesodweb/persistent.svg?branch=master)](https://travis-ci.org/yesodweb/persistent) ![Hackage](https://img.shields.io/hackage/v/persistent.svg) ![Hackage-Deps](https://img.shields.io/hackage-deps/v/persistent.svg)
+# Persistent [![Build Status](https://travis-ci.org/yesodweb/persistent.svg?branch=master)](https://travis-ci.org/yesodweb/persistent) ![Hackage](https://img.shields.io/hackage/v/persistent.svg) ![Hackage-Deps](https://img.shields.io/hackage-deps/v/persistent.svg) [![Join the chat at https://gitter.im/yesodweb/persistent](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/yesodweb/persistent?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 A Haskell datastore. Datastores are often referred to as "ORM"s. While 'O' traditionally means object, the concept can be generalized as:
 
@@ -11,6 +9,69 @@ In dynamic languages rather than compile time errors, safety comes from creating
 
 Persistent's goal is to catch every possible error at compile-time, and it comes close to that.
 
+# Quickstart
+
+<details>
+<summary>
+Click to show package.yaml part.
+Learn more at <a href="https://www.yesodweb.com/book/persistent" target="_blank">http://www.yesodweb.com/book/persistent.</a>
+</summary>
+
+```yaml
+dependencies:
+- base ^>= 4.17
+- text ^>= 2
+- persistent ^>= 2.14
+- persistent-sqlite ^>= 2.13
+```
+
+</details>
+<p></p>
+
+```haskell
+{-# LANGUAGE EmptyDataDecls             #-}
+{-# LANGUAGE FlexibleContexts           #-}
+{-# LANGUAGE GADTs                      #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE OverloadedStrings          #-}
+{-# LANGUAGE QuasiQuotes                #-}
+{-# LANGUAGE TemplateHaskell            #-}
+{-# LANGUAGE TypeFamilies               #-}
+import           Control.Monad.IO.Class  (liftIO)
+import           Database.Persist
+import           Database.Persist.Sqlite
+import           Database.Persist.TH
+import           Data.Text
+
+share [mkPersist sqlSettings, mkMigrate "migrateAll"] [persistLowerCase|
+Person
+    name Text
+    age Int Maybe
+    deriving Show
+|]
+
+main :: IO ()
+main = runSqlite ":memory:" $ do
+    -- setup db schema
+    runMigration migrateAll
+
+    -- write to db
+    insert $ Person "Jane Doe" Nothing
+    johnId <- insert $ Person "John Doe" $ Just 35
+
+    -- read from db
+    john1 <- selectList [PersonId ==. johnId] [LimitTo 1]
+    john2 <- get johnId
+
+    liftIO $ print (john1 :: [Entity Person])
+    liftIO $ print (john2 :: Maybe Person)
+
+    -- delete from db
+    delete johnId
+    deleteWhere [PersonId ==. johnId]
+```
+
 # Backend agnostic
 
 Supports PostgreSql, Sqlite, MongoDB, Redis, ZooKeeper, and many other databases via [persistent-odbc](https://github.com/gbwey/persistent-odbc).
@@ -27,15 +88,12 @@ Key-value stores such as Redis can be used with persistent, but only fill out th
 Persistent provides several hooks to create backend-specific functionality.
 One can always fall back to using the raw database driver or other lower-level or less type-safe libraries and can utilize Persistent for un-serializing the database response to a Haskell record.
 
+# Help improve Persistent
 
-## Install from source
-
-Clone the repo and run `stack build` to build all targets. Persistent
+To install from source clone the repo and run `stack build` to build all targets. Persistent
 supports many backends. If you have only some of these installed the
 [development doc](development.md) shows how to build against a subset of
 targets.
 
-## Development
-
-For more information on how to hack ont he `persistent` set of libraries, see
+For more information on how to hack on the `persistent` set of libraries, see
 the [`development.md`](development.md) file.