title: What are the status tags, like [build | passing]
body: <p>May be a well known question, but actually I'm asking this, because I'm not familiar with these tags.</p>
  
  <p><a href="https://i.stack.imgur.com/RPcfw.png" rel="noreferrer"><img src="https://i.stack.imgur.com/RPcfw.png" alt="status tags"></a></p>
  
  <p>I've seen similar types of tags in various Github projects, especially in their <code>README.md</code>. My questions are manifold regarding these:</p>
  
  <ol>
  <li>What's the purpose of these tags?</li>
  <li>How to generate them?</li>
  <li>Is there any good practice or documentation that suggests what types of tags can be used or should be used in a project?</li>
  <li>When a project can be determined viable using such a tag?</li>
  </ol>