title: Autoprefixer not using "grid: autoplace" with cssnano and postcss
body: <p>We are using postcss with cssnano and autoprefixer. My problem is that postcss does not use the "grid: autoplace" in my <code>postcss.config.js</code>.</p>
  
  <p>This is my postcss.config.js:</p>
  
  <pre><code>const cssnano = require('cssnano');
  const mqpacker = require('css-mqpacker');
  const postcssPresetEnv = require('postcss-preset-env');
  
  module.exports = (ctx) =&gt; ({
    map: ctx.options.map,
    parser: false,
    plugins: [
      postcssPresetEnv(),
      mqpacker({ sort: true }),
      cssnano({
        preset: [
          'advanced',
          {
            autoprefixer: {
              add: true,
              grid: 'autoplace',
            },
            reduceIdents: false,
            zindex: false,
          },
        ],
      }),
    ],
  });
  </code></pre>
  
  <p>On the other hand, when I add <code>/* autoprefixer grid: autoplace */</code> to my css file and run:</p>
  
  <pre><code>postcss ./dist/*.css --verbose &gt; test.css
  </code></pre>
  
  <p>Postcss uses grid and adds the <code>-ms</code> prefixes.
  Why is it ignoring the property in the config file?</p>