Add code of conduct.

Author: Scinawa

CODE_OF_CONDUCT.md

@@ -1,4 +1,4 @@
-# Contributor Covenant Code of Conduct
+# Contributors' Code of Conduct for quantumalgorithms.org
 
 ## Our Pledge
 
@@ -70,7 +70,6 @@ members of the project's leadership.
 This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
 available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
 
-[homepage]: https://www.contributor-covenant.org
 
 For answers to common questions about this code of conduct, see
 https://www.contributor-covenant.org/faq