Change 'of' back to 'for'

src/sage_docbuild/conf.py

@@ -461,7 +461,7 @@ def linkcode_resolve(domain, info):
         ver += f' built with GitHub PR <a href="{pr_url}">#{pr_number}</a>' \
                f' on <a href="{pr_commit}">{pr_sha[:7]}</a>' \
                f' [<a href="/changes.html">changes</a>]'
-    banner = f'This is documentation of Sage version {ver} for development purpose.'
+    banner = f'This is documentation for Sage version {ver} for development purpose.'
     html_theme_options.update({ "announcement": banner })
 
 # The name of the Pygments (syntax highlighting) style to use. This