CONTRIBUTING.md

CONTRIBUTING to Poly-filters.

1. Create a new filter by analogy the length filter.
2. Pay attention on the template initialization.
3. testWrapper takes two arguments. The first is a object with a parameters that will be inject in the template. The second argument is a callback that returns the element with the parameter result.
4. When all tests have passed, add the filter in poly-filters.html and README.md.
5. Switch to the branch "gh-pages" and update the documentation for your filter.
6. PROFIT!!!!