add json example of packer config

website/content/docs/configure.mdx

@@ -51,7 +51,7 @@ Packer files. The config dir of packer will be looked up on the following paths:
 |-----------------------------|-----------------------------|
 | `PACKER_HOME_DIR/.packer.d` | `PACKER_HOME_DIR/packer.d/` |
 
-Examples: 
+Examples:
 * On a 'unix' system, if the `$PACKER_CONFIG_DIR` env var is set to
 `/home/packer`, the config directory will be: `/home/packer/.packer.d/` and
 other values will not be checked.
@@ -94,6 +94,18 @@ configuration file. None of these are required, since all have defaults.
   and the [`packer init`](/docs/commands/init) command to install plugins; if
   you are using both, the `required_plugin` config will take precedence.
 
+Example Packer config:
+
+```
+{
+  "plugin_min_port": 11000,
+  "plugin_max_port": 25000,
+  "provisioners": {
+    "foo": "/Users/example/packer-provisioner-foo"
+  }
+}
+```
+
 ## Full list of Environment Variables usable for Packer
 
 Packer uses a variety of environmental variables. A listing and description of