doc: add BMP and HDR to the file format list.

That's everything stb_image_write supports.

doc/file-formats.dox

@@ -123,6 +123,22 @@ Together with @ref file-formats-scene-importers "scene importers" derived from
 </tr>
 <tr><td colspan="6"></td></tr>
 
+<tr>
+<th rowspan="2">Radiance HDR<br/>(`*.hdr`)</th>
+<td rowspan="2">`HdrImporter`</td>
+<td>@ref Trade::StbImageImporter "StbImageImporter"</td>
+<td class="m-text-center">@m_span{m-text m-dim} none @m_endspan </td>
+<td class="m-text-center m-primary">bundled</td>
+<td class="m-text-center m-primary">public domain</td>
+</tr>
+<tr>
+<td>@ref Trade::DevIlImageImporter "DevIlImageImporter"</td>
+<td class="m-text-center">@m_span{m-text m-dim} none @m_endspan </td>
+<td class="m-text-center m-danger">external</td>
+<td class="m-text-center m-warning">LGPLv2.1</td>
+</tr>
+<tr><td colspan="6"></td></tr>
+
 <tr>
 <th rowspan="2">ICO<br/>(`*.ico`, `*.cur`)</th>
 <td rowspan="2">`IcoImporter`</td>
@@ -257,6 +273,16 @@ Derived from @ref Trade::AbstractImageConverter.
 </tr>
 <tr><td colspan="6"></td></tr>
 
+<tr>
+<th>Windows Bitmap (`*.bmp`)</th>
+<td>`BmpImageConverter`</td>
+<td>@ref Trade::StbImageConverter "StbImageConverter"</td>
+<td class="m-text-center m-dim">unknown</td>
+<td class="m-text-center m-primary">bundled</td>
+<td class="m-text-center m-primary">public domain</td>
+</tr>
+<tr><td colspan="6"></td></tr>
+
 <tr>
 <th>OpenEXR (`*.exr`)</th>
 <td>`OpenExrImageConverter`</td>
@@ -267,6 +293,16 @@ Derived from @ref Trade::AbstractImageConverter.
 </tr>
 <tr><td colspan="6"></td></tr>
 
+<tr>
+<th>Radiance HDR (`*.hdr`)</th>
+<td>`HdrImageConverter`</td>
+<td>@ref Trade::StbImageConverter "StbImageConverter"</td>
+<td class="m-text-center">@m_span{m-text m-dim} none @m_endspan </td>
+<td class="m-text-center m-primary">bundled</td>
+<td class="m-text-center m-primary">public domain</td>
+</tr>
+<tr><td colspan="6"></td></tr>
+
 <tr>
 <th rowspan="2">JPEG<br/>(`*.jpg`, `*.jpe`, `*.jpeg`)</th>
 <td rowspan="2">`JpegImageConverter`</td>
@@ -317,9 +353,6 @@ Derived from @ref Trade::AbstractImageConverter.
 
 @endparblock
 
-In addition to the above, @ref Trade::StbImageConverter "StbImageConverter"
-supports additional formats.
-
 @section file-formats-scene-importers Scene importers
 
 Together with @ref file-formats-image-importers "image-importers" derived from