title: TextMobject is not defined in Manim
body: <p>I just started to learn manim and I saw the first video in which we create a class in example_scenes.py. When i tried running it, it is saying that name <code>TextMobject</code> is not defined. What should I do?</p>
  <p>Class I created:</p>
  <pre><code>class FirstScene(Scene):
      def construct(self):
          text=TextMobject(&quot;text&quot;)
          self.add(text) 
  </code></pre>
  <p>Code used in conda prompt:</p>
  <pre><code>python -m manim example_scenes.py FirstScene -w
  </code></pre>
  <p>Please check <a href="https://drive.google.com/file/d/1Wz0X8bzpv_KeqLDdCpecoeYzC-oMLAbp/view?usp=sharing" rel="noreferrer">this file</a> for the class &quot;FirstScene&quot; (last class of this file) i am trying to run.</p>