JavaScript-like Anonymous function support

[aminnairi]

It would be great to be able to create an anonymous function using this plugin for JavaScript and other language that have a similiar syntax.

This could use a let g:vim_surround_lambda_bracket_symbol = " {}" for setting the lambda (anonymous) function bracket style per-language.

This could also be using the l letter for specifying the lambda expression like ysiwl. Used in a word like options this would ideally output function(options) {}.

Do you think this is possible? Is it too much?