Revert "Document gitaly network architecture"

This reverts commit cc735352.

I pushed this commit to master accidentally. Oops!

doc/administration/gitaly/index.md

@@ -49,25 +49,6 @@ Starting with GitLab 11.4, Gitaly is a replacement for NFS except
 when the [Elastic Search indexer](https://gitlab.com/gitlab-org/gitlab-elasticsearch-indexer)
 is used.
 
-### Network architecture
-
--   gitlab-rails shards repositories into "repository storages"
--   gitlab-rails/config/gitlab.yml contains a map from storage names to
-    (Gitaly address, Gitaly token) pairs
--   the `storage name` -\> `(Gitaly address, Gitaly token)` map in
-    gitlab.yml is the single source of truth for the Gitaly network
-    topology
--   a (Gitaly address, Gitaly token) corresponds to a Gitaly server
--   a Gitaly server hosts one or more storages
--   Gitaly addresses must be specified in such a way that they resolve
-    correctly for ALL Gitaly clients
--   Gitaly clients are: unicorn, sidekiq, gitlab-workhorse,
-    gitlab-shell, and Gitaly itself
--   special case: a Gitaly server must be able to make RPC calls **to
-    itself** via its own (Gitaly address, Gitaly token) pair as
-    specified in gitlab-rails/config/gitlab.yml
--   Gitaly servers must not be exposed to the public internet
-
 Gitaly network traffic is unencrypted so you should use a firewall to
 restrict access to your Gitaly server.