html_spelllang.vim
This filetype plugin for HTML searches for <html>, <body>, and <main>
elements, and attempts to set the 'spelllang' option appropriately if it
detects that spelling files exist corresponding to any lang= attribute
defined for the lattermost instances of these elements within the first 128
lines.
License
Copyright (c) Tom Ryder. Distributed under the same terms as Vim itself.
See :help license.