Upload Defold SDK and reference documentation to GitHub on release (#…

…7538)

* Upload sdk and ref doc to GitHub

* Update release_to_github.py

build_tools/release_to_github.py

@@ -148,7 +148,7 @@ def is_editor_file(path):
                                           'Defold-x86_64-win32.zip')
 
     def is_main_file(path):
-        return os.path.basename(path) in ('bob.jar',) or is_editor_file(path)
+        return os.path.basename(path) in ('bob.jar', 'ref-doc.zip') or is_editor_file(path) or 'engine/defoldsdk.zip' in path
 
     def is_platform_file(path):
         return os.path.basename(path) in ('gdc',