title: RegEx to find characters starting and ending with a hashtag / pound sign?
body: <p>Given as string like:</p>
  
  <pre><code>"I #am# taking my big #brown# dog for a #walk# in the park"
  </code></pre>
  
  <p>I need a regex that would return this collection of strings:</p>
  
  <pre><code>#am#
  #brown#
  #walk#
  </code></pre>
  
  <p>It would be nice if it would ignore standalone hashtags (i.e. if it finds a space before the next "#", skip it and look for the next match).</p>
  
  <p>Thanks for any help.</p>