Allow apache formula to set env varibles from mod_env and
mod_setenvif modules

Prod-Related: PROD-36176
Change-Id: Ibb735bf3759558677475d6f9b867efc6c7545b93
diff --git a/README.rst b/README.rst
index fb6b4ae..ced8f6f 100644
--- a/README.rst
+++ b/README.rst
@@ -186,6 +186,31 @@
             limits:
               request_body: 114688
 
+Apache environment modules (mod_env, mod_setendif).
+
+.. code-block:: yaml
+
+    apache:
+      server:
+        site:
+          horizon:
+            env:
+              passenv:
+              - variable: LC_ALL
+                enabled: False
+              setenv:
+              - variable: X-Forwarded-Proxy
+                value: somehost
+                enabled: False
+              unsetenv:
+              - variable: LC_LOCAL
+            envif:
+              browsermatch:
+              - rule: ^MSIE mozilla
+              setenvif:
+              - rule: X-Forwarded-Proto https HTTPS=1
+                enabled: False
+
 Apache redirect site definition.
 
 .. code-block:: yaml