title: Serilog's AddSerilog is not recognized
body: <p>I'm trying to call <strong>loggerFactory.AddSerilog();</strong> as per <a href="https://github.com/serilog/serilog-docker/blob/master/web-sample/src/Program.cs" rel="noreferrer">this</a> documentation, but the <strong>AddSerilog</strong> method is not recognized:</p>
  <p>&quot;Error  CS1061  'ILoggerFactory' does not contain a definition for 'AddSerilog' and no extension method 'AddSerilog' accepting a first...&quot;.</p>
  <p>I'm using ASP.NET CORE with the full .NET framework.
  What am I doing wrong?</p>