Documentation: Interpolation from environment with wrong syntax

The documentation says: 

```
$[env:my_env_variable] to reference the environment variable named my_env_variable
```

My experience and experiments say, the syntax is rather

```
${env.my_env_variable} to reference the environment variable named my_env_variable
```

with curly braces `${}` and a dot `.` after the namespace. 

Checked on AEMaaCS - local SDK. 

(Is it different on 6.5? )

