Bring usage docs up to date

website/source/intro/getting-started/install.html.markdown

@@ -46,18 +46,20 @@ $ terraform
 usage: terraform [--version] [--help] <command> [<args>]
 
 Available commands are:
-    apply      Builds or changes infrastructure
-    destroy    Destroy Terraform-managed infrastructure
-    get        Download and install modules for the configuration
-    graph      Create a visual graph of Terraform resources
-    init       Initializes Terraform configuration from a module
-    output     Read an output from a state file
-    plan       Generate and show an execution plan
-    refresh    Update local state file against real resources
-    remote     Configure remote state storage
-    show       Inspect Terraform state or plan
-    taint      Manually mark a resource for recreation
-    version    Prints the Terraform version
+    apply       Builds or changes infrastructure
+    destroy     Destroy Terraform-managed infrastructure
+    get         Download and install modules for the configuration
+    graph       Create a visual graph of Terraform resources
+    init        Initializes Terraform configuration from a module
+    output      Read an output from a state file
+    plan        Generate and show an execution plan
+    push        Upload this Terraform module to Atlas to run
+    refresh     Update local state file against real resources
+    remote      Configure remote state storage
+    show        Inspect Terraform state or plan
+    taint       Manually mark a resource for recreation
+    validate    Validates the Terraform files
+    version     Prints the Terraform version
 ```
 
 If you get an error that `terraform` could not be found, then your PATH