README.md in anyway_config-1.2.0 vs README.md in anyway_config-1.3.0

@@ -87,10 +87,30 @@
     attr_config user: 'root', password: 'root', host: 'localhost', options: {}
   end
 end
 ```
 
+#### Customize env variable names prefix
+
+By default, Anyway Config will use config name with stripped underscores as a prefix for env variable names (e.g.
+`config_name :my_app` will result to parsing `MYAPP_HOST` variable, not `MY_APP_HOST`). You can set env prefix
+explicitly, and it will be used as is:
+
+```ruby
+module MyCoolGem
+  class Config < Anyway::Config
+    config_name :cool_gem
+    env_prefix :really_cool # now variables, starting wih `REALLY_COOL_`, will be parsed
+    attr_config user: 'root', password: 'root', host: 'localhost', options: {}
+  end
+end
+```
+
+**DEPRECATION WARNING** In the 1.4 version no stripping will be applied on config_names by default, so if you use explicit config names with
+underscores and use env variables, your app will be broken. In this case it is recommended to start using `env_prefix`
+now.
+
 #### Provide explicit values
 
 Sometimes it's useful to set some parameters explicitly during config initialization.
 You can do that using `overrides` option:
 
@@ -174,10 +194,10 @@
 - `"nil"` and `"null"` to `nil` (do you really need it?);
 
 - `"123"` to 123 and `"3.14"` to 3.14.
 
 *Anyway Config* supports nested (_hashed_) env variables. Just separate keys with double-underscore.
-For example, "MYCOOLGEM_OPTIONS__VERBOSE" is parsed as `config.options.verbose`.
+For example, "MYCOOLGEM_OPTIONS__VERBOSE" is parsed as `config.options["verbose"]`.
 
 Array values are also supported:
 
 ```ruby
 # Suppose ENV["MYCOOLGEM_IDS"] = '1,2,3'