title: discord.py Dsiplay guild's icon using icon_url
body: <p>I am trying to get the guild's icon url. How do i use icon_url to grab the link?</p>
  
  <pre class="lang-py prettyprint-override"><code>@client.command()
  async def servericon(ctx):
      await ctx.send(discord.Guild.icon_url)
  </code></pre>
  
  <p>I expected to get guild's icon url, but got "property object at 0x000002683BB548B8" this instead.</p>