docs: fix some broken markdown links (#8021)

Found by the link checker.

There are still some links that aren't fixed, because it's not clear where they _should_ point. I just hit the obvious ones.

docs/architecture/adr-044-lite-client-with-weak-subjectivity.md

@@ -84,7 +84,7 @@ The linear verification algorithm requires downloading all headers
 between the `TrustHeight` and the `LatestHeight`. The lite client downloads the
 full header for the provided `TrustHeight` and then proceeds to download `N+1`
 headers and applies the [Tendermint validation
-rules](https://docs.tendermint.com/master/spec/light-client/verification/)
+rules](https://github.com/tendermint/tendermint/tree/master/spec/light-client/verification/README.md)
 to each block.
 
 ### Bisecting Verification

docs/architecture/adr-045-abci-evidence.md

@@ -18,7 +18,7 @@ graceful here, but that's for another day.
 
 It's possible to fool lite clients without there being a fork on the
 main chain - so called Fork-Lite. See the
-[fork accountability](https://docs.tendermint.com/master/spec/light-client/accountability/)
+[fork accountability](https://github.com/tendermint/tendermint/blob/master/spec/light-client/accountability/README.md)
 document for more details. For a sequential lite client, this can happen via
 equivocation or amnesia attacks. For a skipping lite client this can also happen
 via lunatic validator attacks. There must be some way for applications to punish

docs/roadmap/roadmap.md

@@ -47,7 +47,7 @@ An overhaul of the existing interface between the application and consensus, to
 
 ### Proposer-Based Timestamps
 
-Proposer-based timestamps are a replacement of [BFT time](https://docs.tendermint.com/master/spec/consensus/bft-time.html), whereby the proposer chooses a timestamp and validators vote on the block only if the timestamp is considered *timely*. This increases reliance on an accurate local clock, but in exchange makes block time more reliable and resistant to faults. This has important use cases in light clients, IBC relayers, CosmosHub inflation and enabling signature aggregation. [More](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-071-proposer-based-timestamps.md)
+Proposer-based timestamps are a replacement of [BFT time](https://github.com/tendermint/tendermint/blob/master/spec/consensus/bft-time.md), whereby the proposer chooses a timestamp and validators vote on the block only if the timestamp is considered *timely*. This increases reliance on an accurate local clock, but in exchange makes block time more reliable and resistant to faults. This has important use cases in light clients, IBC relayers, CosmosHub inflation and enabling signature aggregation. [More](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-071-proposer-based-timestamps.md)
 
 ### RPC Event Subscription
 

docs/tutorials/go-built-in.md

@@ -212,7 +212,7 @@ etc.) by Tendermint Core.
 
 Valid transactions will eventually be committed given they are not too big and
 have enough gas. To learn more about gas, check out ["the
-specification"](https://docs.tendermint.com/master/spec/abci/apps.html#gas).
+specification"](https://github.com/tendermint/tendermint/blob/master/spec/abci/apps.md#gas).
 
 For the underlying key-value store we'll use
 [badger](https://github.com/dgraph-io/badger), which is an embeddable,
@@ -331,7 +331,7 @@ func (app *KVStoreApplication) Query(reqQuery abcitypes.RequestQuery) (resQuery
 ```
 
 The complete specification can be found
-[here](https://docs.tendermint.com/master/spec/abci/).
+[here](https://github.com/tendermint/tendermint/tree/master/spec/abci/).
 
 ## 1.4 Starting an application and a Tendermint Core instance in the same process
 

docs/tutorials/go.md

@@ -210,7 +210,7 @@ etc.) by Tendermint Core.
 
 Valid transactions will eventually be committed given they are not too big and
 have enough gas. To learn more about gas, check out ["the
-specification"](https://docs.tendermint.com/master/spec/abci/apps.html#gas).
+specification"](https://github.com/tendermint/tendermint/blob/master/spec/abci/apps.md#gas).
 
 For the underlying key-value store we'll use
 [badger](https://github.com/dgraph-io/badger), which is an embeddable,
@@ -328,7 +328,7 @@ func (app *KVStoreApplication) Query(reqQuery abcitypes.RequestQuery) (resQuery
 ```
 
 The complete specification can be found
-[here](https://docs.tendermint.com/master/spec/abci/).
+[here](https://github.com/tendermint/tendermint/tree/master/spec/abci/).
 
 ## 1.4 Starting an application and a Tendermint Core instances