docs: changelog instruction removed from docs (#7395)

changelog instruction removed from docs

dev-docs/docs/introduction/contributing.mdx

@@ -52,15 +52,6 @@ Make sure the title starts with a semantic prefix:
 - **chore**: Other changes that don't modify src or test files
 - **revert**: Reverts a previous commit
 
-### Changelog
-
-Add a brief description of your pull request to the changelog located here: [changelog](https://github.com/excalidraw/excalidraw/blob/master/CHANGELOG.md)
-
-Notes:
-
-- Make sure to prepend to the section corresponding with the semantic prefix you selected in the title
-- Link to your pull request - this will require updating the CHANGELOG _after_ creating the pull request
-
 ### Testing
 
 Once you submit your pull request it will automatically be tested. Be sure to check the results of the test and fix any issues that arise.