GITBOOK-312: Update Stacking data links

Author: cuevasm

concepts/block-production/stacking.md

@@ -156,11 +156,14 @@ The Stacks website has a [stacking page](https://www.stacks.co/learn/stacking) d
 
 For detailed instructions on how to stack, view the [Stack STX guides](../../guides-and-tutorials/stack-stx/).
 
-### Stacking Data
-
 You can view all sorts of Stacking data and statistics using tools in the ecosystem such as:
 
 * [Signal21](https://app.signal21.io/)
 * [Stacking Tracker](https://www.stacking-tracker.com/)
 * [StakingRewards.com](https://www.stakingrewards.com/calculator?asset=stacks)
 * [Stacking Calendar](https://stacking.tools/)
+
+- [Signal21](https://app.signal21.io/)
+- [Stacking Tracker](https://www.stacking-tracker.com/)
+- [StakingRewards.com](https://www.stakingrewards.com/calculator?asset=stacks)
+- [Stacking Calendar](https://stacking.tools/)