updating with license, adding note about not being an 'intro' book, r…

…elocating 'contributing' guidelines

CONTRIBUTING.md

@@ -1 +1,7 @@
-Please see [Contributions](https://github.com/getify/functional-light-js#contributions).
+Please feel free to contribute to the quality of this content by submitting PR's for improvements to code snippets, explanations, etc. If there's any doubt or if you think that a word/phrase is used confusingly, **before submitting a PR, open an issue to ask about it.**
+
+However, if you choose to contribute content (not just typo corrections) to this repo, you agree that you're giving me a non-exclusive license to use that content for the book, as I (and any future publisher) deem appropriate. You probably guessed that already, but I just have to make sure the lawyers are happy by explicitly stating it.
+
+This book will go through official editing eventually, and typos will likely all be caught at that stage. As such, **typos are not a big concern of mine for now**. If you're going to PR for typo fixes, please be measured in doing so by collecting several small changes into a single PR (in separate commits). Or, **just don't even worry about them for now,** because we'll get to them later. I promise.
+
+Also, if you have any questions or concerns, please make sure to search the issues (both open and closed!) first, to keep the churn of issues to a minimum. I want to keep my focus on writing the book as much as possible.