Add large_client_header_buffers to proxy.conf

Add posibility to change large_client_header_buffers parameter

Related-PROD: PROD-36448
Change-Id: I84a03be43516b1ffe9bec13d44d47ebdf725c353
diff --git a/README.rst b/README.rst
index 630b919..33736b9 100644
--- a/README.rst
+++ b/README.rst
@@ -491,6 +491,25 @@
               name: gitlab.domain.com
               port: 80
 
+If we need to read large client request headers, we need to add new
+parameter `large_client_header_buffers` with buffers number and size:
+.. code-block:: yaml
+    nginx:
+      server:
+        enabled: true
+        bind:
+          address: '0.0.0.0'
+          ports:
+          - 80
+        site:
+          gitlab_proxy:
+            enabled: true
+            type: nginx_proxy
+            large_client_header_buffers: '4 8k'
+            host:
+              name: gitlab.domain.com
+              port: 80
+
 Let's Encrypt:
 
 .. code-block:: yaml