website: update docs for powershell

plugins/commands/powershell/command.rb

@@ -13,7 +13,7 @@ module VagrantPlugins
         options = {}
 
         opts = OptionParser.new do |o|
-          o.banner = "Usage: vagrant ps [-- extra ps args]"
+          o.banner = "Usage: vagrant powershell [-- extra powershell args]"
 
           o.separator ""
           o.separator "Options:"

website/docs/source/layouts/layout.erb

@@ -103,6 +103,7 @@
 									<li<%= sidebar_current("cli-login") %>><a href="/v2/cli/login.html">login</a></li>
 									<li<%= sidebar_current("cli-package") %>><a href="/v2/cli/package.html">package</a></li>
 									<li<%= sidebar_current("cli-plugin") %>><a href="/v2/cli/plugin.html">plugin</a></li>
+									<li<%= sidebar_current("cli-powershell") %>><a href="/v2/cli/powershell.html">powershell</a></li>
 									<li<%= sidebar_current("cli-provision") %>><a href="/v2/cli/provision.html">provision</a></li>
 									<li<%= sidebar_current("cli-rdp") %>><a href="/v2/cli/rdp.html">rdp</a></li>
 									<li<%= sidebar_current("cli-reload") %>><a href="/v2/cli/reload.html">reload</a></li>

website/docs/source/v2/cli/powershell.html.md

@@ -0,0 +1,19 @@
+---
+page_title: "vagrant powershell - Command-Line Interface"
+sidebar_current: "cli-powershell"
+---
+
+# PowerShell
+
+**Command: `vagrant powershell`**
+
+This will open a PowerShell prompt into a running Vagrant machine.
+
+This command will only work if the machine supports PowerShell. Not every
+environment will support PowerShell.
+
+## Options
+
+* `-c COMMAND` or `--command COMMAND` - This executes a single PowerShell command,
+  prints out the stdout and stderr, and exits.
+