Update search-domain-services.md

docs/software-developer-documentation/legacy-server-side-extensions/search-domain-services.md

 Search Domain Services
 ======================
 
+|                |ASCII                          |HTML                         |
+|----------------|-------------------------------|-----------------------------|
+|Single backticks|`'Isn't this fun?'`            |'Isn't this fun?'            |
+|Quotes          |`"Isn't this fun?"`            |<table>  <thead>  <tr>  <th></th>  <th>ASCII</th>  <th>HTML</th>  </tr>  </thead>  <tbody>  <tr>  <td>Single backticks</td>  <td><code>'Isn't this fun?'</code></td>  <td>‘Isn’t this fun?’</td>  </tr>  <tr>  <td>Quotes</td>  <td><code>"Isn't this fun?"</code></td>  <td>“Isn’t this fun?”</td>  </tr>  <tr>  <td>Dashes</td>  <td><code>-- is en-dash, --- is em-dash</code></td>  <td>– is en-dash, — is em-dash</td>  </tr>  </tbody>  </table>      |
+|Dashes          |`-- is en-dash, --- is em-dash`|-- is en-dash, --- is em-dash|
+
 A search domain service is a DSS plugin which allows to query some
 domain specific search services. For example, a search service on a
 database of nucleotide acid sequences. Currently only one search service