Add linting for pipeline files

[ptitzler]

• Add a make task that lints .pipeline files to enforce best practices.
• Add new task as a dependency for existing lint task

[ptitzler]

To verify that a pipeline comment.pipeline contains a description one could use .jq:

cat comment.pipeline| jq -e '.pipelines[] | select(.id == "primary") | .app_data.properties.description?'