chore: Added example for how to build container images with different architectures (#344)

Co-authored-by: Anton Babenko <anton@antonbabenko.com>

Author: GonzalezAndrew

README.md

@@ -580,7 +580,7 @@ Q4: What does this error mean - `"We currently do not support adding policies fo
 ## Examples
 
 - [Complete](https://github.com/terraform-aws-modules/terraform-aws-lambda/tree/master/examples/complete) - Create Lambda resources in various combinations with all supported features.
-- [Container Image](https://github.com/terraform-aws-modules/terraform-aws-lambda/tree/master/examples/container-image) - Create Docker image (using [docker provider](https://registry.terraform.io/providers/kreuzwerker/docker)), push it to AWS ECR, and create Lambda function from it.
+- [Container Image](https://github.com/terraform-aws-modules/terraform-aws-lambda/tree/master/examples/container-image) - Create a Docker image with a platform specified in the Dockerfile (using [docker provider](https://registry.terraform.io/providers/kreuzwerker/docker)), push it to AWS ECR, and create Lambda function from it.
 - [Build and Package](https://github.com/terraform-aws-modules/terraform-aws-lambda/tree/master/examples/build-package) - Build and create deployment packages in various ways.
 - [Alias](https://github.com/terraform-aws-modules/terraform-aws-lambda/tree/master/examples/alias) - Create static and dynamic aliases in various ways.
 - [Deploy](https://github.com/terraform-aws-modules/terraform-aws-lambda/tree/master/examples/deploy) - Complete end-to-end build/update/deploy process using AWS CodeDeploy.

examples/container-image/context/Dockerfile

@@ -1,4 +1,5 @@
-FROM scratch
+# `--platform` argument is used to be able to build docker images when using another platform (e.g. Apple M1)
+FROM --platform=linux/x86_64 scratch
 
 ARG FOO
 

examples/container-image/main.tf

@@ -34,8 +34,9 @@ module "lambda_function_from_container_image" {
   ##################
   # Container Image
   ##################
-  image_uri    = module.docker_image.image_uri
-  package_type = "Image"
+  image_uri     = module.docker_image.image_uri
+  package_type  = "Image"
+  architectures = ["x86_64"]
 }
 
 module "docker_image" {