Update doc/install/structure.md

doc/install/structure.md

-## Description of GitLab structure
+# GitLab directory structure
 
-
-### Directory structure
+This is the directory structure you will end up with following the instructions in the Installation Guide.
 
     |-- home
     |   |-- gitlab
+    |       |-- .ssh
     |       |-- gitlab
     |       |-- gitlab-satellites
     |   |-- git
-    |       |-- repositories
     |       |-- .gitolite
+    |       |-- .ssh
+    |       |-- bin
+    |       |-- gitolite
+    |       |-- repositories
+
+
+**/home/gitlab/.ssh**
+  Contains the Gitolite admin key GitLab uses to configure Gitolite.
+
+**/home/gitlab/gitlab**
+  This is where GitLab lives.
+
+**/home/gitlab/gitlab-satellites**
+  Contains a copy of all repositories with a working tree.
+  It's used for merge requests, editing files, etc.
 
+**/home/git/.ssh**
+  Contains the SSH access configuration managed by Gitolite.
 
-gitlab
-  Holds all the code of gitlab application.
+**/home/git/bin**
+  Contains Gitolite executables.
 
-gitlab-satellites
-  Contains a copy of all repositories with working tree. 
-  Used to automatically merge requests, edit files etc...
+**/home/git/gitolite**
+  This is where Gitolite lives.
 
-repositories
-  Keeps all you repositories in bare format here
+**/home/git/repositories**
+  Holds all your repositories in bare format.
+  This is the place Git uses when you pull/push to your projects.
 
+You can change them in your `config/gitlab.yml` file.