doc: mark OpenEXR as bundleable.

The docs include a CMake snippet that bundles everything. Before it said
"tiny" which is wrong -- libJPEG or libPNG are tiny, this is not.

doc/file-formats.dox

@@ -127,7 +127,7 @@ Together with @ref file-formats-scene-importers "scene importers" derived from
 <td rowspan="2">`OpenExrImporter`</td>
 <td>@ref Trade::OpenExrImporter "OpenExrImporter"</td>
 <td class="m-text-center m-warning">@ref Trade-OpenExrImporter-behavior "some"</td>
-<td class="m-text-center m-warning">external, tiny</td>
+<td class="m-text-center m-warning">bundleable</td>
 <td class="m-text-center m-success">BSD 3-clause</td>
 </tr>
 <tr>
@@ -329,7 +329,7 @@ Derived from @ref Trade::AbstractImageConverter.
 <td rowspan="2">`OpenExrImageConverter`</td>
 <td>@ref Trade::OpenExrImageConverter "OpenExrImageConverter"</td>
 <td class="m-text-center m-warning">@ref Trade-OpenExrImageConverter-behavior "some"</td>
-<td class="m-text-center m-warning">external, tiny</td>
+<td class="m-text-center m-warning">bundleable</td>
 <td class="m-text-center m-success">BSD 3-clause</td>
 </tr>
 <tr>