updated changelog

Author: briri

CHANGELOG.md

@@ -5,8 +5,10 @@
 - Added CHANGELOG.md and Danger Github Action [#3257](https://github.com/DMPRoadmap/roadmap/issues/3257)
 - Added validation with custom error message in research_output.rb to ensure a user does not enter a very large value as 'Anticipated file size'. [#3161](https://github.com/DMPRoadmap/roadmap/issues/3161)
 - Added popover for org profile page and added explanation for public plan
+
 ### Fixed
 
+- Fixed an issue that was preventing uses from leaving the research output byte_size field blank
 - Froze mail gem version [#3254](https://github.com/DMPRoadmap/roadmap/issues/3254)
 - Updated the CSV export so that it now includes research outputs
 - Updated sans-serif font used in PDF downloads to Roboto since Google API no longer offers Helvetica