优化主题外观，新增high-contrast主题

themes/theme.py

@@ -5,6 +5,9 @@ THEME, = get_conf('THEME')
 if THEME == 'Chuanhu-Small-and-Beautiful':
     from .green import adjust_theme, advanced_css
     theme_declaration = "<h2 align=\"center\"  class=\"small\">[Chuanhu-Small-and-Beautiful主题]</h2>"
+elif THEME == 'High-Contrast':
+    from .contrast import adjust_theme, advanced_css
+    theme_declaration = ""
 else:
     from .default import adjust_theme, advanced_css
     theme_declaration = ""