.jshintrc

extensions: avoid including `__index__` in the disabled extension list

This generated module contains a dictionary of all bundled extension names and
their help for builds that cannot enumerate extensions in the filesystem.

The disabled list gets displayed in `hg help extensions`, and is also used by
`setup.py` to populate `__index__.py` when building.  I haven't seen it sneak
into either py2exe or PyOxidizer builds, but it does show up when running tests
locally after having created an installer.

Differential Revision: https://phab.mercurial-scm.org/D9544

{
    // 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)
}