Improve Contribution Doc (#2043)

* first refactor

* more text

* improve

* finish

* up

* up

* up

* up

* finish

* Apply suggestions from code review

Co-authored-by: Sayak Paul <[email protected]>
Co-authored-by: YiYi Xu <[email protected]>

* up

* Apply suggestions from code review

Co-authored-by: Pedro Cuenca <[email protected]>

* finished

* Apply suggestions from code review

Co-authored-by: Pedro Cuenca <[email protected]>

* finished

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Co-authored-by: Sayak Paul <[email protected]>
Co-authored-by: YiYi Xu <[email protected]>
Co-authored-by: Pedro Cuenca <[email protected]>

Author: 4 people

CODE_OF_CONDUCT.md

@@ -24,7 +24,7 @@ community include:
 * Accepting responsibility and apologizing to those affected by our mistakes,
   and learning from the experience
 * Focusing on what is best not just for us as individuals, but for the
-  overall community
+  overall diffusers community
 
 Examples of unacceptable behavior include:
 
@@ -34,6 +34,7 @@ Examples of unacceptable behavior include:
 * Public or private harassment
 * Publishing others' private information, such as a physical or email
   address, without their explicit permission
+* Spamming issues or PRs with links to projects unrelated to this library
 * Other conduct which could reasonably be considered inappropriate in a
   professional setting