Add options and fix spelling on CONTRIBUTING.md

Created by: vndmtrx

CONTRIBUTING.md

@@ -7,5 +7,9 @@ Your contributions are always welcome!
 * Add section if needed
     * Add section description
     * Add section title to Table of contents
-* Add your links: `* [project-name](http://example.com/) - A short descripttion ends with a dot.`
+* Search previous suggestions before making a new one, as yours may be a duplicate.
+* Add your links: `* [project-name](http://example.com/) - A short description ends with a dot.`
+* Don't mention `Python` in the description as it's implied.
+* Check your spelling and grammar.
+* Make sure your text editor is set to remove trailing whitespace.
 * Send a Pull Request