Update contributor guide with emoji for clarity (#1028)

Author: brunoborges

docs/contributors.md

@@ -6,13 +6,13 @@ We have prepared a short guide so that the process of making your contribution i
 
 ## How can I contribute...
 
-* [Contribute Documentation:green_book:](#contribute-documentation)
+* [:green_book: Contribute Documentation](#contribute-documentation)
 
-* [Contribute Code :computer:](#contribute-code)
+* [:computer: Contribute Code](#contribute-code)
 
-* [Provide Support on Issues:pencil:](#provide-support-on-issues)
+* [:pencil: Provide Support on Issues](#provide-support-on-issues)
 
-* [Review Pull Requests:mag:](#review-pull-requests)
+* [:mag: Review Pull Requests](#review-pull-requests)
 
 ## Contribute documentation
 
@@ -111,4 +111,4 @@ Another great way to contribute is is to review pull request. Please, be extra k
 - Make sure you're familiar with the code or documentation is updated, unless it's a minor change (spellchecking, minor formatting, etc.)
 - Review changes using the GitHub functionality. You can ask a clarifying question, point out an error or suggest an alternative. 
 > Note: You may ask for minor changes - "nitpicks", but consider whether they are real blockers to merging or not
-- Submit your review, which may include comments, an approval, or a changes request
+- Submit your review, which may include comments, an approval, or a changes request