Include an example in the readme

README.md

@@ -18,6 +18,65 @@ while providing the full flexibility of Postgres Range types inside of Ecto.
 | tstzrange     | `EctoRange.TimestampTZ` |
 | daterange     | `EctoRange.Date`        |
 
+## Usage
+
+`EctoRange` provides custom types, and can be used like any other Ecto type.
+
+```elixir
+defmodule MyApp.Repo.Migrations.AddRange do
+  use Ecto.Migration
+
+  def change do
+    create table(:my_table) do
+      add :name, :string
+      add :range, :daterange
+    end
+  end
+end
+
+defmodule MyApp.Table do
+  use Ecto.Schema
+
+  import Ecto.Changeset
+
+  schema "my_table" do
+    field(:name, :string)
+    field(:range, EctoRange.Date)
+  end
+
+  def changeset(table, params) do
+    table
+    |> cast(params, [:name, :range])
+    |> validate_required([:name, :range])
+  end
+end
+
+iex> alias MyApp.Table
+
+iex> range = Date.range(~D[1989-09-22], ~D[2021-03-01])
+
+iex> cs = Table.changeset(%Table{}, %{name: "table", range: range}}
+
+iex> cs.changes
+%Ecto.Changeset{
+  changes: %{
+    range: %Postgrex.Range{
+      lower: ~D[1989-09-22],
+      upper: ~D[2021-03-01],
+      lower_inclusive: true,
+      upper_inclusive: true
+    },
+    name: "name"
+  },
+  data: %MyApp.Table{id: nil, name: nil, range: nil},
+  params: %{
+    "range" => Date.range(~D[1989-09-22], ~D[2021-03-01]),
+    "name" => "name"
+  },
+  valid?: true
+}
+```
+
 ## Installation
 
 If [available in Hex](https://hex.pm/docs/publish), the package can be installed