fix repo linter issue (#15)

README.md

@@ -1,4 +1,4 @@
-[![Community Plus header](https://github.com/newrelic/opensource-website/raw/main/src/images/categories/Community_Plus.png)](https://opensource.newrelic.com/oss-category/#community-plus)
+<a href="https://opensource.newrelic.com/oss-category/#community-project"><picture><source media="(prefers-color-scheme: dark)" srcset="https://github.com/newrelic/opensource-website/raw/main/src/images/categories/dark/Community_Project.png"><source media="(prefers-color-scheme: light)" srcset="https://github.com/newrelic/opensource-website/raw/main/src/images/categories/Community_Project.png"><img alt="New Relic Open Source community project banner." src="https://github.com/newrelic/opensource-website/raw/main/src/images/categories/Community_Project.png"></picture></a>
 
 
 # New Relic Unity Agent