Fixes yiisoft#245: Adjusted explanation of what -local.php configs ar…

…e to make it cleaner

docs/guide/structure-environments.md

@@ -16,9 +16,11 @@ By default there are two environments: `dev` and `prod`. First is for developmen
 and debug turned on. Second is for server deployments. It has debug and developer tools turned off. 
 
 Typically environment contains application bootstrap files such as `index.php` and config files suffixed with
-`-local.php`. These are either personal configs of team members which are usually in `dev` environment or configs of
-specific servers. For example, production database connection could be in `prod` environment `-local.php` config.
-These local configs are added to `.gitignore` and never pushed to source code repository.
+`-local.php`. Local configs in `environments` directory are templates that, after `init` is executed, 
+are being copied into corresponding application config directories. After that, they become your local configuration.
+They are meant to keep secret and environment-specific settings, such as database connection credentials,
+and aren't meant to be put into version control system. Thus these files are added to `.gitignore` so git is not
+considering them for staging.
 
 In order to avoid duplication configurations are overriding each other. For example, the frontend reads configuration in the
 following order: