template: Add a note on shadowed symbols

Mention that a symbol can shadow another symbol, and that a symbol can be
shadowed by another symbol.

This information is mostly relevant to users of language bindings.

gidocgen/templates/basic/function.html

@@ -87,6 +87,12 @@ SPDX-License-Identifier: Apache-2.0 OR GPL-3.0-or-later
           {% if not func.introspectable %}
           <tr><td>This function is not directly available to language bindings</td></tr>
           {% endif %}
+          {% if func.shadows %}
+          <tr><td>This function is renamed to <a href="func.{{func.shadows}}.html"><code>{{func.shadows_symbol}}()</code></a> in language bindings</td></tr>
+          {% endif %}
+          {% if func.shadowed_by %}
+          <tr><td>The implementation of this function is provided by <a href="func.{{func.shadowed_by}}.html"><code>{{func.shadowed_by_symbol}}()</code></a> in language bindings</td></tr>
+          {% endif %}
         </table>
       </div>
 

gidocgen/templates/basic/method.html

@@ -82,6 +82,12 @@ SPDX-License-Identifier: Apache-2.0 OR GPL-3.0-or-later
           {% if not method.introspectable %}
           <tr><td>This method is not directly available to language bindings.</td></tr>
           {% endif %}
+          {% if method.shadows %}
+          <tr><td>This method is renamed to <a href="method.{{class.name}}.{{method.shadows}}.html"><code>{{method.shadows_symbol}}()</code></a> in language bindings</td></tr>
+          {% endif %}
+          {% if method.shadowed_by %}
+          <tr><td>The implementation of this method is provided by <a href="method.{{class.name}}.{{method.shadowed_by}}.html"><code>{{method.shadowed_by_symbol}}()</code></a> in language bindings</td></tr>
+          {% endif %}
         </table>
       </div>