Update submod_versioning.md html-blank added

doc/versioning/submod_versioning.md

@@ -440,7 +440,7 @@ the .gitmodules file was created or extended.</td>
 </thead>
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-<td>git clone &lt;url&gt;--recurse-submodules</td>
+<td>git clone &lt;url&gt; &nbsp; --recurse-submodules</td>
 <td><p>Initial cloning of a repository including all submodules. This is
 achieved by using the "--recurse-submodules" option.</p>