docs: change invalid link (#4158)

* fix typo backwards-compatibility.md

"seperately" -> "separately"

* docs: fix invalid link staking-rewards.md

The link [turbine](https://www.youtube.com/watch?v=qt_gDRXHrHQ&t=1s) is not appropriate because it is a private video. 

Therefore, it seems appropriate to substitute [turbine](https://docs.anza.xyz/consensus/turbine-block-propagation) for the video link.

* fix invalid link validator-start.md

"[metrics dashboard](https://metrics.solana.com:3000/d/monitor/cluster-telemetry)" is invalid.

Changed to "[metrics dashboard](https://metrics.solana.com:3000/d/monitor-edge/cluster-telemetry)"

docs/src/implemented-proposals/staking-rewards.md

@@ -24,7 +24,7 @@ To become a Solana validator, one must deposit/lock-up some amount of SOL in a c
 
 - _Cool-down period_: a duration of time following the submission of a 'withdrawal' transaction. During this period validation responsibilities have been removed and the funds continue to be inaccessible. Accumulated rewards should be delivered at the end of this period, along with the return of the initial deposit.
 
-Solana's trustless sense of time and ordering provided by its PoH data structure, along with its [turbine](https://www.youtube.com/watch?v=qt_gDRXHrHQ&t=1s) data broadcast and transmission design, should provide sub-second transaction confirmation times that scale with the log of the number of nodes in the cluster. This means we shouldn't have to restrict the number of validating nodes with a prohibitive 'minimum deposits' and expect nodes to be able to become validators with nominal amounts of SOL staked. At the same time, Solana's focus on high-throughput should create incentive for validation clients to provide high-performant and reliable hardware. Combined with potentially a minimum network speed threshold to join as a validation-client, we expect a healthy validation delegation market to emerge.
+Solana's trustless sense of time and ordering provided by its PoH data structure, along with its [turbine](https://docs.anza.xyz/consensus/turbine-block-propagation) data broadcast and transmission design, should provide sub-second transaction confirmation times that scale with the log of the number of nodes in the cluster. This means we shouldn't have to restrict the number of validating nodes with a prohibitive 'minimum deposits' and expect nodes to be able to become validators with nominal amounts of SOL staked. At the same time, Solana's focus on high-throughput should create incentive for validation clients to provide high-performant and reliable hardware. Combined with potentially a minimum network speed threshold to join as a validation-client, we expect a healthy validation delegation market to emerge.
 
 ## Penalties
 

docs/src/operations/guides/validator-start.md

@@ -26,7 +26,7 @@ to your machine by fetching the transaction count:
 solana transaction-count
 ```
 
-View the [metrics dashboard](https://metrics.solana.com:3000/d/monitor/cluster-telemetry) for more
+View the [metrics dashboard](https://metrics.solana.com:3000/d/monitor-edge/cluster-telemetry) for more
 detail on cluster activity.
 
 ## Enabling CUDA