title: add space between 2 strings
body: <p>I would like to add <code>whitespace</code> between a <code>.</code> and <code>number</code>.</p>
  <p>My exampe as below</p>
  <pre><code>df &lt;- data.frame(name1 = c(&quot;Acranthera sp.01&quot;, &quot;Aglaia spectabilis (Miq.) S.S.Jain &amp; Bennet&quot;, &quot;Alyxia sp.11&quot;))
  
  df
                                         name1
  1                            Acranthera sp.01
  2 Aglaia spectabilis (Miq.) S.S.Jain &amp; Bennet
  3                                Alyxia sp.11
  </code></pre>
  <p>My desired output</p>
  <pre><code>                                       name1
  1                            Acranthera sp. 01
  2 Aglaia spectabilis (Miq.) S.S.Jain &amp; Bennet
  3                                Alyxia sp. 11
  </code></pre>
  <p>So far, I only know to use <code>str_pad</code> to add the space. Any sugesstions for this with <code>tidyverse</code> and <code>stringr</code>?</p>