Add HCL Examples & Docs (#852)

Fixes https://github.com/pulumi/pulumi-docker-build/issues/844

provider/internal/embed/index-examples.md

@@ -327,6 +327,60 @@ resources:
         type: docker-build:Index
 runtime: yaml
 ```
+```hcl
+pulumi {
+  required_providers {
+    docker-build = {
+      source  = "pulumi/docker-build"
+      version = "0.0.15"
+    }
+  }
+}
+
+resource "docker-build_image" "amd64" {
+  cache_from {
+    registry = {
+      ref = "docker.io/pulumi/pulumi:cache-amd64"
+    }
+  }
+  cache_to {
+    registry = {
+      mode = "max"
+      ref  = "docker.io/pulumi/pulumi:cache-amd64"
+    }
+  }
+  context = {
+    location = "app"
+  }
+  platforms = ["linux/amd64"]
+  tags      = ["docker.io/pulumi/pulumi:3.107.0-amd64"]
+}
+resource "docker-build_image" "arm64" {
+  cache_from {
+    registry = {
+      ref = "docker.io/pulumi/pulumi:cache-arm64"
+    }
+  }
+  cache_to {
+    registry = {
+      mode = "max"
+      ref  = "docker.io/pulumi/pulumi:cache-arm64"
+    }
+  }
+  context = {
+    location = "app"
+  }
+  platforms = ["linux/arm64"]
+  tags      = ["docker.io/pulumi/pulumi:3.107.0-arm64"]
+}
+resource "docker-build_index" "index" {
+  sources = [docker-build_image.amd64.ref, docker-build_image.arm64.ref]
+  tag     = "docker.io/pulumi/pulumi:3.107.0"
+}
+output "ref" {
+  value = docker-build_index.index.ref
+}
+```
 ```java
 package generated_program;
 
@@ -342,8 +396,8 @@ import com.pulumi.dockerbuild.inputs.CacheToRegistryArgs;
 import com.pulumi.dockerbuild.inputs.BuildContextArgs;
 import com.pulumi.dockerbuild.Index;
 import com.pulumi.dockerbuild.IndexArgs;
-import java.util.List;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Map;
 import java.io.File;
 import java.nio.file.Files;