GH-32: Add explanation for specifying location by states

Author: ArtyomVancyan

docs/integration/settings/index.md

@@ -40,5 +40,5 @@ DJANGO_FORBID = {
 ```
 
 In this example, the Django Forbid will permit access to users using the listed devices and forbid entry to users
-worldwide except for the US, UK, and EU countries. It will also forbid access to the users who use VPN to lie about
+worldwide except for the US, GB, and EU countries. It will also forbid access to the users who use VPN to lie about
 their geolocation. The settings also define the URLs to redirect to when access is forbidden.

docs/integration/settings/variables.md

@@ -43,6 +43,12 @@ The list of countries to permit or forbid access to. The list accepts country co
 the ones starting with the `!` prefix are forbidden. The list of all codes can be
 found [here](https://www.iban.com/country-codes).
 
+Also, you can permit or forbid access to a certain state of the country by specifying the state code after the country
+code is joined with a `:` symbol. For example, `!US:TX` will forbid access to Texas by permitting the rest of the
+mentioned country states. With the same principle, the `US:CA` will permit access to California only. The list of all US
+state codes can be found [here](https://wikipedia.org/wiki/List_of_states_and_territories_of_the_United_States). This
+declaration method can be used with all countries having states/districts.
+
 ## Territories
 
 - Key: `TERRITORIES`