Improve module docs wrt. required params (#36812)

So I am still not satisfied with how required parameters are being
displayed (before it was yes/no, then it became required/optional, and
only required).

Now it will display in small green 'required' under the parameter name.
This is more convenient, and provides more room for the description.
Especially on smaller screens.

docs/templates/plugin.rst.j2

@@ -91,7 +91,6 @@ Options
         {# Header of the documentation #}
         <tr>
             <th class="head"><div class="cell-border">Parameter</div></th>
-            <th class="head"><div class="cell-border">Required?</div></th>
             <th class="head"><div class="cell-border">Default</div></th>
             <th class="head"><div class="cell-border">Choices</div></th>
             {% if plugin_type != 'module' %}
@@ -109,12 +108,12 @@ Options
                             </div>
                         {% endfor %}
                         <div class="elbow-key">
-                            <b>@{ key }@</b><br/><div style="font-size: small;">{% if value.version_added %} (added in @{value.version_added}@){% endif %}</div>
+                            <b>@{ key }@</b>
+                            {% if value.get('required', False) %}<br/><div style="font-size: small; color: red">required</div>{% endif %}
+                            {% if value.version_added %}<br/><div style="font-size: small; color: darkgreen">(added in @{value.version_added}@)</div>{% endif %}
                         </div>
                     <div class="outer-elbow-container">
                 </td>
-                {# required #}
-                <td><div class="cell-border">{% if value.get('required', False) %}required{% endif %}</div></td>
                 {# default value #}
                 <td><div class="cell-border">{% if value.default %}@{ value.default | html_ify }@{% endif %}</div></td>
                 {# choices #}