fix curl call that posts a link to the preview docs to the PR

Author: bcumming

.github/workflows/docs_pr.yaml

@@ -43,7 +43,7 @@ jobs:
           curl -L -X POST \
             -H "Accept: application/vnd.github+json" \
             -H "Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}" \
-            "https://api.github.com/repos/bcumming/kb-poc/issues/${{ github.event.pull_request.number }}/comments" \
+            "https://api.github.com/repos/eth-cscs/cscs-docs/issues/${{ github.event.pull_request.number }}/comments" \
             -d '{
               "body": "preview available: https://docs.tds.cscs.ch/${{ github.event.pull_request.number }}"
             }'