feat(docs): add mention of the new --skip-run flag

Author: rzmk

docs/content/docs/changelog/0.3.1.mdx

@@ -31,3 +31,7 @@ To ensure users using VirtualBox see the full command for adding a user to the s
 ## GitHub Action to verify CKAN install runs
 
 We've added a GitHub Action to run on push to the main branch to verify that a CKAN-only install runs. This doesn't include verbose testing but rather ensuring that the ckan-devstaller finishes without errors.
+
+## New --skip-run flag
+
+We've added a `--skip-run` flag to skip running CKAN at the end of installation.