Update CONTRIBUTING.md

Let's add a few more remarks here.

Author: perlun

CONTRIBUTING.md

@@ -1,6 +1,7 @@
 Thanks for your interest in contributing to the project! Please follow these simple guidelines:
 
-- Please follow existing coding style when submitting pull requests. Most importantly, *use spaces* - do not use tabs (which is the default setting for C++ projects in Visual Studio). The "preview" function when creating a Pull Request on GitHub is very useful - please use it.
+- **Please read the full contents of [the FAQ](https://github.com/cefsharp/CefSharp/wiki/Frequently-asked-questions) before submitting an issue, or posting to the Google Group. It's quite likely your question has already been answered before.** If something is unclear in the FAQ, of course feel free to ask; the idea is just to reduce the level of "noise" we have to go through, reading the same questions over and over again.
 - If you are unsure if something is a "bug" or a "feature", discuss it with the Google Group first. Don't cross-post: if you create an issue, and all the information is contained there, that's perfectly enough. There's no reason to also post it to the group; it just creates "line noise". The project maintainers are very busy people like you and me, and things will sometimes take a few weeks (or in worst case, more) to answer. If you are in a rush - do your very best to investigate the problem thoroughly; if possible, fix the bug yourself and submit a pull request.
 - Before creating a GitHub issue or pull request, try looking through the list & issue archives to make sure the issue at hand hasn't been raised before. [Google](http://www.google.com) can also be helpful: just typing "cefsharp appdomain" for example (when trying to see whether AppDomain support has been discussed before) will often give you helpful results.
+- *Please* follow existing coding style when submitting pull requests. Most importantly, *use spaces* - do not use tabs (which is the default setting for C++ projects in Visual Studio). The "preview" function when creating a Pull Request on GitHub is very useful - please use it.
 - Do your best to follow these guidelines but don't be afraid to make mistakes when trying to apply them. We are all novices in the beginning.