Add email contribution option to CONTRIBUTING.md (fixes #192)

Author: WebCoder49

CONTRIBUTING.md

@@ -18,6 +18,8 @@ To keep this community productive and enjoyable, please [don't break our code of
 
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 # Ways you could contribute:
+If you don't want to use GitHub, for all of these you can alternatively [get in touch via email so the maintainer can add your contribution for you](mailto:[email protected]).
+
 ## 1. I've found a bug but don't know how / don't have time to fix it.
 If you think you've found a bug, please [submit an issue](https://github.com/WebCoder49/code-input/issues) with screenshots, how you found the bug, and copies of the console's logs if an error is in them. Please also mention the template and plugins you used (your `codeInput.registerTemplate(...)` snippet). We'd be more than happy to help you fix it. A demo using [CodePen](https://codepen.io/) would be incredibly useful.