Update CONTRIBUTING.md with spam PR notice

Added a note about spam pull requests to the contribution guidelines.

Author: fffaraz

CONTRIBUTING.md

@@ -1,7 +1,8 @@
 # Contribution Guidelines
 Please ensure your pull request adheres to the following guidelines:
 
-* Please note that this is not a comprehensive list of software made with C++; it focuses on libraries and similar resources that can be used in C++ code.
+* **SPAM PR => Instant Block & Report**
+* This is not a comprehensive list of software made with C++; it focuses on libraries that can be used in C++ code.
 * Please search previous suggestions before making a new one, as yours may be a duplicate.
 * Please make an individual pull request for each suggestion.
 * Use the following format: \[RESOURCE\]\(REPO-LINK\) - DESCRIPTION. [LICENSE] \[website\]\(WEB-LINK\)