.jshintrc

narrow: filter files by narrowspec in ctx.matches()

This has no effect yet because 1) for committed changes, ctx.matches()
just calls ctx.walk(), which we updated in the previous patch, and 2)
for the working copy, the filtering is also done in the overridden
dirstate.walk() in narrowdirstate.

Differential Revision: https://phab.mercurial-scm.org/D4899

{
    // Enforcing
    "eqeqeq"        : true,     // true: Require triple equals (===) for comparison
    "forin"         : true,     // true: Require filtering for..in loops with obj.hasOwnProperty()
    "freeze"        : true,     // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
    "nonbsp"        : true,     // true: Prohibit "non-breaking whitespace" characters.
    "undef"         : true,     // true: Require all non-global variables to be declared (prevents global leaks)

    // Environments
    "browser"       : true      // Web Browser (window, document, etc)
}