title: Make span element "editable"
body: <p>I have a <code>span</code> element that I want to become editable upon double-click. (That is, the user can edit the text and it will save when s/he clicks outside.)</p>
  
  <p>The effect I want to emulate is similar to when I double-click CSS properties in the Google Chrome Developer Tools. (See picture.)</p>
  
  <p><img src="https://i.stack.imgur.com/PxdUd.png" alt="enter image description here"></p>