Move cpp includes out of extern "C" block

extensions/include/cmark-gfm-core-extensions.h

@@ -1,16 +1,16 @@
 #ifndef CMARK_GFM_CORE_EXTENSIONS_H
 #define CMARK_GFM_CORE_EXTENSIONS_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include "cmark-gfm-extension_api.h"
 #include "export.h"
 
 #include <stdbool.h>
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 CMARK_GFM_EXPORT
 void cmark_gfm_core_extensions_ensure_registered(void);
 

src/include/module.modulemap

@@ -5,6 +5,7 @@ module cmark_gfm {
     header "buffer.h"
     header "chunk.h"
     header "cmark_ctype.h"
+    header "export.h"
     header "footnotes.h"
     header "houdini.h"
     header "html.h"