`org-edit-special' edits export blocks

* lisp/org.el (org-edit-special): Allow to edit export blocks.
* etc/ORG-NEWS: Document feature.

etc/ORG-NEWS

@@ -103,6 +103,11 @@ default is =hline=.
 One can use a drawer without listing it in the =#+DRAWERS= keyword,
 which is now obsolete.  As a consequence, this change also deprecates
 ~org-drawers~ variable.
+*** ~org-edit-special~  can edit export blocks
+Using C-c ' on an export block now opens a sub-editing buffer.  Major
+mode in that buffer is determined by export backend name (e.g.,
+"latex" \to "latex-mode").  You can define exceptions to this rule by
+configuring ~org-src-lang-modes~, which see.
 *** Markdown export supports switches in source blocks
 For example, it is now possible to number lines using the =-n= switch
 in a source block.

lisp/org.el

@@ -20661,6 +20661,7 @@ See the individual commands for more information."
 When at a table, call the formula editor with `org-table-edit-formulas'.
 When in a source code block, call `org-edit-src-code'.
 When in a fixed-width region, call `org-edit-fixed-width-region'.
+When in an export block, call `org-edit-export-block'.
 When at an #+INCLUDE keyword, visit the included file.
 On a link, call `ffap' to visit the link at point.
 Otherwise, return a user error."
@@ -20698,11 +20699,12 @@ Otherwise, return a user error."
          (user-error "No special environment to edit here")))
       (table
        (if (eq (org-element-property :type element) 'table.el)
-           (org-edit-src-code)
+           (org-edit-table.el)
          (call-interactively 'org-table-edit-formulas)))
       ;; Only Org tables contain `table-row' type elements.
       (table-row (call-interactively 'org-table-edit-formulas))
-      ((example-block export-block) (org-edit-src-code))
+      ((example-block src-block) (org-edit-src-code))
+      (export-block (org-edit-export-block))
       (fixed-width (org-edit-fixed-width-region))
       (otherwise
        ;; No notable element at point.  Though, we may be at a link,