fix file extensions and links

Author: meaghanlewis

docs/core/tools/dotnet-package-update renamed to docs/core/tools/dotnet-package-update.md

@@ -220,7 +220,7 @@ The following options are available only when `dotnet` runs an application by us
 |---------------------------------------------------------|-----------------------------------------------------|
 | [dotnet workload clean](dotnet-workload-clean.md)       | Removes workload components.                        |
 | [dotnet workload config](dotnet-workload-config.md)     | Enables or disables workload-set update mode.       |
-| [dotnet workload history](dotnet-workload-history)      | Shows all workload installation actions.            |
+| [dotnet workload history](dotnet-workload-history.md)   | Shows all workload installation actions.            |
 | [dotnet workload install](dotnet-workload-install.md)   | Installs an optional workload.                      |
 | [dotnet workload list](dotnet-workload-list.md)         | Lists all installed workloads.                      |
 | [dotnet workload repair](dotnet-workload-repair.md)     | Repairs all installed workloads.                    |

docs/core/tools/dotnet.md

@@ -102,10 +102,10 @@ The following commands are installed by default:
 ### Workload management commands
 
 - [`workload`](dotnet-workload.md) (Available since .NET 7 SDK)
-- [`workload clean`](dotnet-workload-clean) (Available since .NET 6 SDK)
+- [`workload clean`](dotnet-workload-clean.md) (Available since .NET 6 SDK)
 - [`workload config`](dotnet-workload-config.md) (Available since .NET 8.0.400 SDK)
 - [`workload install`](dotnet-workload-install.md) (Available since .NET 6 SDK)
-- [`workload history`](dotnet-workload-history) (Available since .NET 6 SDK)
+- [`workload history`](dotnet-workload-history.md) (Available since .NET 6 SDK)
 - [`workload list`](dotnet-workload-list.md) (Available since .NET 6 SDK)
 - [`workload update`](dotnet-workload-update.md) (Available since .NET 6 SDK)
 - [`workload restore`](dotnet-workload-restore.md) (Available since .NET 6 SDK)