request for autocomplete and jump-to-definition for standard library

[ericwang-db]

Jsonnet has one standard library, and it's implicitly bound to the variable std. Two cool features:

• autocompletion of any stdlib methods
• jump to definition for these methods to desugared methods defined in https://github.com/google/jsonnet/blob/master/stdlib/std.jsonnet. Note these methods have 0 documentation, but seeing the method signatures and implementation is still useful as a quick reference.