(#25) Add local compose to the docs

Referenced from https://www.testcontainers.org/modules/docker_compose/

README.md

@@ -158,3 +158,48 @@ if err != nil {
 	// do something with err
 }
 ```
+
+## Using Docker Compose
+
+Similar to generic containers support, it's also possible to run a bespoke set of services specified in a docker-compose.yml file.
+
+This is intended to be useful on projects where Docker Compose is already used in dev or other environments to define services that an application may be dependent upon.
+
+You can override Testcontainers' default behaviour and make it use a docker-compose binary installed on the local machine. This will generally yield an experience that is closer to running docker-compose locally, with the caveat that Docker Compose needs to be present on dev and CI machines.
+
+### Examples
+
+```go
+composeFilePaths := "testresources/docker-compose.yml"
+identifier := strings.ToLower(uuid.New().String())
+
+compose := tc.NewLocalDockerCompose(composeFilePaths, identifier)
+execError := compose.
+	WithCommand([]string{"up", "-d"}).
+	WithEnv(map[string]string {
+		"key1": "value1",
+		"key2": "value2",
+	}).
+	Invoke()
+err := execError.Error
+if err != nil {
+	return fmt.Errorf("Could not run compose file: %v - %v", composeFilePaths, err)
+}
+return nil
+```
+
+Note that the environment variables in the `env` map will be applied, if possible, to the existing variables declared in the docker compose file.
+
+In the following example, we demonstrate how to stop a Docker compose using the convenient `Down` method.
+
+```go
+composeFilePaths := "testresources/docker-compose.yml"
+
+compose := tc.NewLocalDockerCompose(composeFilePaths, identifierFromExistingRunningCompose)
+execError := compose.Down()
+err := execError.Error
+if err != nil {
+	return fmt.Errorf("Could not run compose file: %v - %v", composeFilePaths, err)
+}
+return nil
+```