Add source URL comment to standardized tasks

This will make it easier for the maintainers to sync fixes and improvements in either direction between the upstream
"template" tasks and their installation in this repository.

Author: per1234

Taskfile.yml

@@ -69,6 +69,7 @@ tasks:
       - task: docs:format
       - task: config:format
 
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-go-task/Taskfile.yml
   go:check:
     desc: Check for problems with Go code
     deps:
@@ -103,6 +104,7 @@ tasks:
           {{default "-min_confidence 0.8 -set_exit_status" .GO_LINT_FLAGS}} \
           {{default .DEFAULT_TARGETS .TARGETS}}
 
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-go-task/Taskfile.yml
   go:format:
     desc: Format Go code
     cmds: