[Docs] Fix readthedocs config lint (#384)

docs/conf.py

@@ -77,7 +77,8 @@ master_doc = 'index'
 latex_elements = {
     # Additional stuff for the LaTeX preamble.
     # 'preamble': '',
-'preamble': r'''
+    'preamble':
+    r'''
 \hypersetup{unicode=true}
 \usepackage{CJKutf8}
 \DeclareUnicodeCharacter{00A0}{\nobreakspace}
@@ -95,6 +96,7 @@ latex_elements = {
 ''',
 }
 
+
 def builder_inited_handler(app):
     subprocess.run(['./stat.py'])