Add PowerShell install guide to the website
<h2>Getting started</h2>
<p>Install Deno into ~/.deno/bin
-
+<h2>With Shell</h2>
<pre>
curl -L https://deno.land/x/install/install.sh | sh
export PATH=$HOME/.deno/bin:$PATH
</pre>
+<h2>With PowerShell</h2>
+<pre>
+iex (iwr https://deno.land/x/install/install.ps1)
+</pre>
Try a Deno program. Install by bash alias.
This one serves a local directory in HTTP.
