5b76c314d6 doc: Add separate productivity notes document (Carl Dong)
Pull request description:
Many developers have their own tools and tricks to be more productive
during their cycles, so let's document the best ones so that everyone
can benefit from them.
Tree-SHA512: b4989e7a815e972a9a646f448fb6c08bd896b4bce77fd7fb22a71a7602971d4cbe34f88183f503f5b851d002784d9e91b87df5348c661eeb9cefa69c52e0de2b
