title: Group_by string vector and add sequential code
body: <p>I'm trying to add a sequential code to the duplicates values by grouping them.
  It is transforming to a prefix and a unique ID for each.</p>
  <pre><code>*IDtest         Desired_ ID*
  2021-11-0515    2021-11-0515-1
  2021-11-0573    2021-11-0573-1
  2021-11-0528    2021-11-0528-1
  2021-11-055     2021-11-055-1
  2021-11-0552    2021-11-0552-1
  2021-11-0562    2021-11-0562-1
  2021-11-0515    2021-11-0515-2
  2021-11-0515    2021-11-0515-3
  2021-11-0528    2021-11-0528-2
  2021-11-0528    2021-11-0528-3
  </code></pre>
  <p>I tried:</p>
  <pre><code>test %&gt;%
  group_by(IDtest) %&gt;%
  paste(IDtest,&quot;-&quot;, seq_along(IDtest) - 1)
  </code></pre>
  <p>I can only get a long array with all the data.</p>
  <p>Thank you.</p>