Revert "multiple major mode support for web editing in Emacs"

The change is reversed.
This is done because it isn't best practice to mix PHP with HTML :(

This reverts commit 0479eaa621.

lisp/init-multi-web.el

@@ -1,10 +0,0 @@
-(use-package multi-web-mode
-  :config
-  (setq mweb-default-major-mode 'html-mode)
-  (setq mweb-tags '((php-mode "<\\?php\\|<\\? \\|<\\?=" "\\?>")
-                  (js-mode "<script +\\(type=\"text/javascript\"\\|language=\"javascript\"\\)[^>]*>" "</script>")
-                  (css-mode "<style +type=\"text/css\"[^>]*>" "</style>")))
-  (setq mweb-filename-extensions '("php" "htm" "html" "ctp" "phtml" "php4" "php5"))
-  (multi-web-global-mode 1))
-
-(provide 'init-multi-web)