Update installation guide with new all-in-one install method

Signed-off-by: James Munnelly <james@munnelly.eu>

docs/getting-started/2-installing.rst

@@ -17,7 +17,7 @@ You can perform these two steps with the following commands:
 
     # Install the cert-manager CRDs
     $ kubectl apply \
-        -f https://raw.githubusercontent.com/jetstack/cert-manager/v0.6.0-alpha.0/deploy/manifests/00-crds.yaml
+        -f https://raw.githubusercontent.com/jetstack/cert-manager/release-0.6/deploy/manifests/00-crds.yaml
 
     # Update helm repository cache
     $ helm repo update
@@ -26,11 +26,11 @@ You can perform these two steps with the following commands:
     $ helm install \
         --name cert-manager \
         --namespace cert-manager \
-        --version v0.6.0-alpha.0 \
+        --version v0.6.0 \
         stable/cert-manager
 
 Each time you upgrade, you will need to re-apply the ``00-crds.yaml`` manifest
-above (updating the version number, in this case ``v0.6.0-alpha.0``, accordingly).
+above (updating the version number, in this case ``v0.6.0``, accordingly).
 
 The default cert-manager configuration is good for the majority of users, but a
 full list of the available options can be found in the `Helm chart README`_.
@@ -55,19 +55,9 @@ To install cert-manager using the static manifests, you should run:
 
 .. code-block:: shell
 
-   # Install the cert-manager CRDs
-   $ kubectl apply \
-        -f https://raw.githubusercontent.com/jetstack/cert-manager/v0.6.0-alpha.0/deploy/manifests/00-crds.yaml
-
-   # Create a namespace to run cert-manager in
-   $ kubectl create namespace cert-manager
-
-   # Disable resource validation on the cert-manager namespace
-   $ kubectl label namespace cert-manager certmanager.k8s.io/disable-validation=true
-
    # Install cert-manager
    $ kubectl apply \
-        -f https://raw.githubusercontent.com/jetstack/cert-manager/v0.6.0-alpha.0/deploy/manifests/cert-manager.yaml
+        -f https://raw.githubusercontent.com/jetstack/cert-manager/release-0.6/deploy/manifests/cert-manager.yaml
 
 .. _`charts repository`: https://github.com/kubernetes/charts
 .. _`Helm chart README`: https://github.com/kubernetes/charts/blob/master/stable/cert-manager/README.md