title: Laravel: Add column to table with updated migration
body: <p>I'm trying to migrate a specific line in one migration file.</p>
  
  <p><strong>Example:</strong></p>
  
  <p>Before:</p>
  
  <pre class="lang-php prettyprint-override"><code>Schema::create('categories', function (Blueprint $table) {
    $table-&gt;bigIncrements('id');
    $table-&gt;string('category_name');
    $table-&gt;integer('parent_id')-&gt;nullable();
    $table-&gt;timestamps();
  });
  </code></pre>
  
  <p>After:</p>
  
  <pre class="lang-php prettyprint-override"><code>Schema::create('categories', function (Blueprint $table) {
    $table-&gt;bigIncrements('id');
    $table-&gt;string('category_name');
    $table-&gt;string('img_url'); // ← new column
    $table-&gt;integer('parent_id')-&gt;nullable();
    $table-&gt;timestamps();
  });
  </code></pre>
  
  <p>And now I just want to migrate the line: <code>$table-&gt;string('img_url');</code></p>
  
  <p>Is it possible?</p>