Added full js & js_util packages

packages/quiver_iterables/CONTRIBUTING.md

 # How to contribute
 
 ### Sign our Contributor License Agreement (CLA)
 
 Even for small changes, we ask that you please sign the CLA electronically
 [here](https://developers.google.com/open-source/cla/individual).
 The CLA is necessary because you own the copyright to your changes, even
 after your contribution becomes part of our codebase, so we need your permission
 to use and distribute your code. You can find more details
 [here](https://code.google.com/p/dart/wiki/Contributing). You'll only need to
 do this once.
 
 ### Contribution Guidelines
 
-We welcome your pull requests, issue reports and enhacement requests. To make
+We welcome your pull requests, issue reports and enhancement requests. To make
 the process as smooth as possible, we request the following:
 
    * Sign the [CLA](https://cla.developers.google.com/about/google-individual)
      (see above) before sending your pull request. It's quick, we promise!
    * Have test cases for your changes and ensure that the existing ones pass in
      checked mode.
-   * Run your changes through `dartformat`. Follow the installation instructions
+   * Run your changes through `dartfmt`. Follow the installation instructions
      in the [dart_style](https://github.com/dart-lang/dart_style) README for
      more info.
    * Squash your commits into a single commit with a good description. You can
      use `git rebase -i` for this. For more details on rebasing, check out
      Atlassian's
      [tutorial](https://www.atlassian.com/git/tutorials/rewriting-history).
    * During code review, go ahead and pile up commits addressing review
      comments. Once you get an LGTM (looks good to me) on the review, we'll ask
      you to squash your commits one last time, then we'll be good to merge!