Started a readme for Dapper.Contrib

Dapper.Contrib/Readme.md

+Dapper.Contrib - more extensions for dapper
+===========================================
+
+Features
+--------
+Dapper.Contrib contains a number of helper methods for inserting, getting, updating and deleting files.
+
+The object you are working with must have a property named Id or a property marked with a [Key] attribute. As with dapper,
+all extension methods assume the connection is already open, they will fail if the connection is closed.
+
+Inserts
+-------
+```csharp
+public static long Insert<T>(this IDbConnection connection, T entityToInsert, IDbTransaction transaction = null, int? commandTimeout = null)
+```
+
+```csharp
+public class Car
+{
+    public int Id { get; set; }
+    public string Name { get; set; }
+}
+    
+connection.Insert(new Car { Name = "Volvo" });
+```
+
+Gets
+-------
+```csharp
+public static T Get<T>(this IDbConnection connection, dynamic id, IDbTransaction transaction = null, int? commandTimeout = null)
+```
+
+```csharp
+var car = connection.Get<Car>(1);
+```
+
+Updates
+-------
+```csharp
+public static bool Update<T>(this IDbConnection connection, T entityToUpdate, IDbTransaction transaction = null, int? commandTimeout = null) 
+```
+
+```csharp
+connection.Update(new Car() { Id = 1, Name = "Saab" });
+```
+
+Deletes
+-------
+```csharp
+public static bool Delete<T>(this IDbConnection connection, T entityToDelete, IDbTransaction transaction = null, int? commandTimeout = null)
+public static bool DeleteAll<T>(this IDbConnection connection, IDbTransaction transaction = null, int? commandTimeout = null)
+```
+
+```csharp
+connection.Delete(new Car() { Id = 1 });
+connection.DeleteAll<Car>();
+```
+
+Attributes
+----------
+Dapper.Contrib makes use of some optional attributes:
+
+* Table("Tablename") - use another table name instead of the name of the class
+* Key - this property is the identity/key (unless it is named "Id")
+* Write(true/false) -  this property is (not) writeable
+* Computed - this property is computed and should not be part of updates