Merge pull request #3264 from Uaitt/docs/add-missing-period

docs(validation): add missing period

Author: kamilmysliwiec

content/techniques/validation.md

@@ -100,7 +100,7 @@ In addition to these, all `class-validator` options (inherited from the `Validat
   <tr>
     <td><code>always</code></td>
     <td><code>boolean</code></td>
-    <td>Set default for <code>always</code> option of decorators. Default can be overridden in decorator options</td>
+    <td>Set default for <code>always</code> option of decorators. Default can be overridden in decorator options.</td>
   </tr>
 
   <tr>