This commit renames the `static` attribute to `namespace` and simultaneously
reduces and expands the scope. The `namespace` attribute can now be applied to
all imports in addition to functions, and it no longer recognizes full typed
paths but rather just a bare identifier. The `namespace` attribute will generate
a Rust namespace to invoke the item through if one doesn't already exist (aka
bindign a type).
Right now Webpack probably has the most mature support for loading wasm modules,
so let's show off how to do that! Additionally this commits hello world as an
example to the repository.
