Number and rename markdown haeders

Number markdown headers to indicate the steps that need to be followed
in order to deploy a new stack:

- 0 - Prerequisite
- 1 - Configuration
- 3 - Deploy

Bug: Issue 10359
Change-Id: I6b22ff35df090d2ae2df06de53c857a212f5dd83
diff --git a/dual-master/README.md b/dual-master/README.md
index 2c6d4d9..f6191ea 100644
--- a/dual-master/README.md
+++ b/dual-master/README.md
@@ -62,11 +62,11 @@
 
 ## How to run it
 
-### Prerequisites
+### 0 - Prerequisites
 
 Follow the steps described in the [Prerequisites](../Prerequisites.md) section
 
-### Configuration
+### 1 - Configuration
 
 Each recipe provides a `setup.env.template` file which is a template for configuring the Gerrit stacks.
 Copy that into a `setup.env` and set the correct values for the  provided environment variables.
@@ -99,7 +99,7 @@
   See [Gerrit documentation](https://gerrit-review.googlesource.com/Documentation/config-gerrit.html#core.packedGitLimit)
   for more details. `12g` by default.
 
-### Getting Started
+### 2 - Deploy
 
 * Create the cluster, services and DNS routing stacks:
 
diff --git a/master-slave/README.md b/master-slave/README.md
index d1abbf1..dbf84e2 100644
--- a/master-slave/README.md
+++ b/master-slave/README.md
@@ -54,11 +54,11 @@
 
 ## How to run it
 
-### Prerequisites
+### 0 - Prerequisites
 
 Follow the steps described in the [Prerequisites](../Prerequisites.md) section
 
-### Configuration
+### 1 - Configuration
 
 Each recipe provides a `setup.env.template` file which is a template for configuring the Gerrit stacks.
 Copy that into a `setup.env` and set the correct values for the  provided environment variables.
@@ -95,7 +95,7 @@
 `CLUSTER_DESIRED_CAPACITY` value to at least 2. The resources provided by
 a single EC2 instance won't be enough for all the services that will be ran*
 
-### Getting Started
+### 2 - Deploy
 
 * Create the cluster, services and DNS routing stacks:
 
diff --git a/single-master/README.md b/single-master/README.md
index d1de278..4d2e624 100644
--- a/single-master/README.md
+++ b/single-master/README.md
@@ -56,11 +56,11 @@
 
 However, keep reading this guide for a more exhaustive explanation.
 
-### Prerequisites
+### 0 - Prerequisites
 
 Follow the steps described in the [Prerequisites](../Prerequisites.md) section
 
-### Configuration
+### 1 - Configuration
 
 Each recipe provides a `setup.env.template` file which is a template for configuring the Gerrit stacks.
 Copy that into a `setup.env` and set the correct values for the  provided environment variables.
@@ -90,7 +90,7 @@
   See [Gerrit documentation](https://gerrit-review.googlesource.com/Documentation/config-gerrit.html#core.packedGitLimit)
   for more details. `12g` by default.
 
-### Getting Started
+### 2 - Deploy
 
 * Create the cluster, service and DNS routing stacks: