docs: Update slashing docs (#22107)

(cherry picked from commit dda9679)

x/slashing/README.md

@@ -143,7 +143,7 @@ bonded validator. The `SignedBlocksWindow` parameter defines the size
 The information stored for tracking validator liveness is as follows:
 
 ```protobuf reference
-https://github.com/cosmos/cosmos-sdk/blob/release/v0.52.x/x/slashing/proto/cosmos/slashing/v1beta1/slashing.proto#L13-L35
+https://github.com/cosmos/cosmos-sdk/blob/v0.52.0-beta.1/x/slashing/proto/cosmos/slashing/v1beta1/slashing.proto#L13-L35
 ```
 
 ### Params
@@ -154,7 +154,7 @@ it can be updated with governance or the address with authority.
 * Params: `0x00 | ProtocolBuffer(Params)`
 
 ```protobuf reference
-https://github.com/cosmos/cosmos-sdk/blob/release/v0.52.x/x/slashing/proto/cosmos/slashing/v1beta1/slashing.proto#L37-L62
+https://github.com/cosmos/cosmos-sdk/blob/v0.52.0-beta.1/x/slashing/proto/cosmos/slashing/v1beta1/slashing.proto#L37-L62
 ```
 
 ## Messages
@@ -312,6 +312,7 @@ The following hooks impact the slashing state:
 * `AfterValidatorBonded` creates a `ValidatorSigningInfo` instance as described in the following section.
 * `AfterValidatorCreated` stores a validator's consensus key.
 * `AfterValidatorRemoved` removes a validator's consensus key.
+* `AfterConsensusPubKeyUpdate` handles the rotation of signing info and updates the address-pubkey relation after a consensus key update.
 
 ### Validator Bonded
 
@@ -633,6 +634,20 @@ Example:
 simd tx slashing unjail --from mykey
 ```
 
+#### update-params-proposal
+
+The `update-params-proposal` command allows users to submit a governance proposal to update the slashing module parameters:
+
+```bash
+simd tx slashing update-params-proposal <params> [flags]
+```
+
+Example:
+
+```bash
+simd tx slashing update-params-proposal '{ "signed_blocks_window": "100" }'
+```
+
 ### gRPC
 
 A user can query the `slashing` module using gRPC endpoints.