Update dropdown file format with extension

Signed-off-by: Yukai Huang <yukaihuangtw@gmail.com>

Author: Yukaii

public/views/shared/pandoc-export-modal.ejs

@@ -11,16 +11,16 @@
                 <div class="modal-body">
                     <strong><%= __('Select output format') %></strong>
                     <select name="output" id="output" class="form-control">
-                        <option value="asciidoc">asciidoc</option>
-                        <option value="context">context</option>
-                        <option value="epub">epub</option>
-                        <option value="epub3">epub3</option>
-                        <option value="latex">latex</option>
-                        <option value="odt">odt</option>
-                        <option value="rst">rst</option>
-                        <option value="rtf">rtf</option>
-                        <option value="textile">textile</option>
-                        <option value="docx">docx</option>
+                        <option value="asciidoc">AsciiDoc</option>
+                        <option value="context">ConTeXt</option>
+                        <option value="epub">EPUB (.epub)</option>
+                        <option value="epub3">EPUB v3 (.epub3)</option>
+                        <option value="latex">LaTeX</option>
+                        <option value="odt">OpenOffice (.odt)</option>
+                        <option value="rst">reStructuredText (.rst)</option>
+                        <option value="rtf">Rich Text Format (.rtf)</option>
+                        <option value="textile">Textile</option>
+                        <option value="docx">Word (.docx)</option>
                     </select>
                 </div>
                 <div class="modal-footer">