updates README with example usage

addresses #15

Author: jazzyb

README.md

@@ -1,4 +1,64 @@
-Sqlite.Ecto
+Sqlite.Ecto [![Build Status](https://travis-ci.org/jazzyb/sqlite_ecto.svg?branch=master "Build Status")](https://travis-ci.org/jazzyb/sqlite_ecto)
 ==========
 
-** TODO: Add description **
+`Sqlite.Ecto` is a SQLite3 Adapter for Ecto.  Here is an example usage:
+
+```elixir
+# In your config/config.exs file
+config :my_app, Repo, database: "db/ecto_simple.sqlite3"
+
+# In your application code
+defmodule Repo do
+  use Ecto.Repo,
+    otp_app: :my_app,
+    adapter: Sqlite.Ecto
+end
+
+defmodule Weather do
+  use Ecto.Model
+
+  schema "weather" do
+    field :city     # Defaults to type :string
+    field :temp_lo, :integer
+    field :temp_hi, :integer
+    field :prcp,    :float, default: 0.0
+  end
+end
+
+defmodule Simple do
+  import Ecto.Query
+
+  def sample_query do
+    query = from w in Weather,
+          where: w.prcp > 0 or is_nil(w.prcp),
+         select: w
+    Repo.all(query)
+  end
+end
+```
+
+## Usage
+
+Add Tds as a dependency in your `mix.exs` file.
+
+```elixir
+def deps do
+  [{:sqlite_ecto, "~> 0.1"}]
+end
+```
+
+You should also update your applications list to include both projects:
+```elixir
+def application do
+  [applications: [:logger, :sqlite_ecto, :ecto]]
+end
+```
+
+To use the adapter in your repo:
+```elixir
+defmodule MyApp.Repo do
+  use Ecto.Repo,
+    otp_app: :my_app,
+    adapter: Sqlite.Ecto
+end
+```