fix broken link in docs and rename OG randomness doc

docs/build/advanced-concepts/randomness.md

@@ -1,6 +1,6 @@
 ---
-title: Flow On-chain Randomness 
-sidebar_label: VRF (Randomness)
+title: Flow On-chain Randomness in Cadence
+sidebar_label: VRF (Randomness) in Cadence
 ---
 
 # Randomness on FLOW
@@ -199,4 +199,4 @@ If you’d like to dive deeper into Flow’s onchain randomness, here’s a list
 - These documents provide a more in-depth technical understanding of the updates and enhancements to the Flow blockchain.
     - **[FLIP 120: Update unsafeRandom function](https://github.com/onflow/flips/blob/main/cadence/20230713-random-function.md#flip-120-update-unsaferandom-function)**
     - **[FLIP 123: On-chain Random beacon history for commit-reveal schemes](https://github.com/onflow/flips/blob/main/protocol/20230728-commit-reveal.md#flip-123-on-chain-random-beacon-history-for-commit-reveal-schemes)**
-- To see working Cadence code, explore the [coin toss example on GitHub](https://github.com/onflow/random-coin-toss/tree/update-prg-impl).
+- To see working Cadence code, explore the [coin toss example on GitHub](https://github.com/onflow/random-coin-toss).