docs: fix broken links (cosmos#21751)

UPGRADING.md

@@ -44,7 +44,7 @@ To be able to simulate nested messages within a transaction, message types conta
 the nested messages. By implementing this interface, the BaseApp can simulate these nested messages during
 transaction simulation. 
 
-## [v0.52.x](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.52.0-alpha.0)
+## [v0.52.x](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.52.0-beta.1)
 
 Documentation to migrate an application from v0.50.x to server/v2 is available elsewhere.
 It is additional to the changes described here.
@@ -53,7 +53,7 @@ It is additional to the changes described here.
 
 In this section we describe the changes made in Cosmos SDK' SimApp.
 **These changes are directly applicable to your application wiring.**
-Please read this section first, but for an exhaustive list of changes, refer to the [CHANGELOG](./simapp/CHANGELOG.md).
+Please read this section first, but for an exhaustive list of changes, refer to the [CHANGELOG](https://github.com/cosmos/cosmos-sdk/blob/main/simapp/CHANGELOG.md).
 
 #### Client (`root.go`)
 
@@ -195,7 +195,9 @@ Grpc-web embedded client has been removed from the server. If you would like to
 
    This indicates that Envoy has started and is ready to proxy requests.
 
+	<!-- markdown-link-check-disable -->
 6. Update your client applications to connect to Envoy (http://localhost:8080 by default).
+	<!-- markdown-link-check-enable -->
 
 </details>
 

docs/rfc/rfc-006-handlers.md

@@ -24,7 +24,7 @@ This has led us to look at a design which would allow the usage of TinyGo and
 other technologies.
 
 We looked at TinyGo for our first target in order to compile down to a 32 bit environment which could be used with
-things like [Risc-0](https://www.risczero.com/), [Fluent](https://fluentlabs.xyz/) and other technologies. When speaking with the teams behind these technologies
+things like [Risc-0](https://www.risczero.com/), [Fluent](https://fluent.xyz/) and other technologies. When speaking with the teams behind these technologies
 we found that they were interested in using the Cosmos SDK but were unable to due to being unable to use TinyGo or the
 Cosmos SDK go code in a 32 bit environment.