docs: improve link

Author: kenjis

user_guide_src/source/general/configuration.rst

@@ -63,6 +63,8 @@ One of today's best practices for application setup is to use Environment Variab
 
 Environment Variables should also be used for anything private such as passwords, API keys, or other sensitive data.
 
+.. _dotenv-file:
+
 Environment Variables and CodeIgniter
 =====================================
 

user_guide_src/source/general/environments.rst

@@ -35,7 +35,7 @@ This can be set in several ways depending on your server setup.
 .env
 ----
 
-The simplest method to set the variable is in your :doc:`.env file </general/configuration>`.
+The simplest method to set the variable is in your :ref:`.env file <dotenv-file>`.
 
 .. code-block:: ini