website: Activate HCL syntax highlighting for Random provider docs

website/source/docs/providers/random/index.html.markdown

@@ -43,7 +43,7 @@ the same until new random values are desired.
 
 For example:
 
-```
+```hcl
 resource "random_id" "server" {
   keepers = {
     # Generate a new id each time we switch to a new AMI id

website/source/docs/providers/random/r/id.html.md

@@ -26,7 +26,7 @@ exist concurrently.
 The following example shows how to generate a unique name for an AWS EC2
 instance that changes each time a new AMI id is selected.
 
-```
+```hcl
 resource "random_id" "server" {
   keepers = {
     # Generate a new id each time we switch to a new AMI id

website/source/docs/providers/random/r/pet.html.md

@@ -21,7 +21,7 @@ exist concurrently.
 The following example shows how to generate a unique pet name for an AWS EC2
 instance that changes each time a new AMI id is selected.
 
-```
+```hcl
 resource "random_pet" "server" {
   keepers = {
     # Generate a new pet name each time we switch to a new AMI id

website/source/docs/providers/random/r/shuffle.html.md

@@ -13,7 +13,7 @@ of strings given as an argument.
 
 ## Example Usage
 
-```
+```hcl
 resource "random_shuffle" "az" {
   input = ["us-west-1a", "us-west-1c", "us-west-1d", "us-west-1e"]
   result_count = 2