fix malformed github markdown json format marker in docs

website/source/docs/builders/googlecompute.html.md

@@ -140,7 +140,7 @@ Or alternatively by navigating to https://console.cloud.google.com/networking/fi
 Once this is set up, the following is a complete working packer config after
 setting a valid `account_file` and `project_id`:
 
-``` {.json}
+``` json
 {
   "builders": [
     {

website/source/docs/builders/oracle-classic.html.md

@@ -98,7 +98,7 @@ Here is a basic example. Note that account specific configuration has been
 obfuscated; you will need to add a working `username`, `password`,
 `identity_domain`, and `api_endpoint` in order for the example to work.
 
-``` {.json}
+``` json
 {
     "builders": [
         {
@@ -137,7 +137,7 @@ for more details on how to define a trusted host.
 
 Save this file as `windows_attributes.json`:
 
-```{.json}
+```json
 {
     "userdata": {
         "administrator_password": "password",
@@ -149,7 +149,7 @@ Save this file as `windows_attributes.json`:
 Following is a minimal but working Packer config that references this attributes
 file:
 
-```{.json}
+```json
 {
     "variables": {
         "opc_username": "{{ env `OPC_USERNAME`}}",

website/source/docs/builders/oracle-oci.html.md

@@ -151,7 +151,7 @@ launched instance.
 Here is a basic example. Note that account specific configuration has been
 substituted with the letter `a` and OCIDS have been shortened for brevity.
 
-``` {.json}
+``` json
 {
     "availability_domain": "aaaa:PHX-AD-1",
     "base_image_ocid": "ocid1.image.oc1.phx.aaaaaaaa5yu6pw3riqtuhxzov7fdngi4tsteganmao54nq3pyxu3hxcuzmoa",