Fix printf flag parsing in version bump workflow (#28)

.github/workflows/deploy-notify.yml

@@ -99,7 +99,14 @@ jobs:
           CANVAS_BULLETS: ${{ steps.changes.outputs.canvas_bullets }}
         run: |
           TODAY=$(TZ=America/New_York date +%Y-%m-%d)
-          MARKDOWN=$(printf "---\n\n## %s — %s\n\n%s" "$VERSION" "$TODAY" "$CANVAS_BULLETS")
+          read -r -d '' MARKDOWN <<ENDMD || true
+          ---
+
+          ## ${VERSION} — ${TODAY}
+
+          ${CANVAS_BULLETS}
+          ENDMD
+          MARKDOWN=$(echo "$MARKDOWN" | sed 's/^          //')
 
           RESPONSE=$(curl -s -X POST https://slack.com/api/canvases.edit \
             -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
@@ -135,8 +142,15 @@ jobs:
           SLACK_BULLETS: ${{ steps.changes.outputs.slack_bullets }}
         run: |
           CANVAS_URL="https://app.slack.com/docs/F0B13V3EBUN"
-          TEXT=$(printf "*After-Hours Scheduler has been updated to %s*\n\nHere's a brief summary of what changed:\n%s\n\n<%s|Click here to read the full changelog>" \
-            "$VERSION" "$SLACK_BULLETS" "$CANVAS_URL")
+          read -r -d '' TEXT <<ENDTXT || true
+          *After-Hours Scheduler has been updated to ${VERSION}*
+
+          Here's a brief summary of what changed:
+          ${SLACK_BULLETS}
+
+          <${CANVAS_URL}|Click here to read the full changelog>
+          ENDTXT
+          TEXT=$(echo "$TEXT" | sed 's/^          //')
 
           curl -s -X POST https://slack.com/api/chat.postMessage \
             -H "Authorization: Bearer $SLACK_BOT_TOKEN" \