[Docs] Existing users and other fixes

* Add a tutorial step about the new existing users feature (step 3)
* Move the corresponding feature request to 'implemented' and modify it a bit
* Rename step 2 to "Rally input task format"
* Add tables of contents to the lessons
* Other fixes that make docs more precise

Change-Id: Ic800fdfa3df883f267ddcae2165f804c11699bd0

doc/feature_request/implemented/LDAP_support.rst

@@ -0,0 +1,30 @@
+===============================================
+Support benchmarking clouds that are using LDAP
+===============================================
+
+Use Case
+--------
+
+A lot of production clouds are using LDAP with read only access. It means
+that load can be generated only by existing in system users and there is no admin access.
+
+
+Problem Description
+-------------------
+
+Rally is using admin access to create temporary users that will be used to
+produce load.
+
+
+Possible Solution
+-----------------
+
+* Add some way to pass already existing users
+
+
+Current Solution
+----------------
+
+* Allow the user to specify existing users in the configuration of the *ExistingCloud* deployment plugin
+* When such an *ExistingCloud* deployment is active, and the benchmark task file does not specify the *"users"* context, use the existing users instead of creating the temporary ones.
+* Modify the *rally show ...* commands to list resources for each user separately.

doc/release_notes/archive/v0.0.3.rst

@@ -147,7 +147,7 @@ Documentation
 
 * New tutorial **task templates**
 
-https://rally.readthedocs.org/en/latest/tutorial/step_4_task_templates.html
+https://rally.readthedocs.org/en/latest/tutorial/step_5_task_templates.html
 
 * Various fixes