Specify directory for --pipeline option?

[Res260]

Currently, it is not supported to use sigma convert --pipeline ./my_pipelines_directory [...]
We're starting to use processing pipelines internally and I wanted to segment processing pipelines by files in a same folder.
Now, when converting, I need to specify manually all the pipelines files, but I think it would be cleaner to be able to specify a directory and that all the YAML pipelines definitions are used in the conversion.

Thoughts?

[thomaspatzke]

Sounds reasonable to me! I marked it as enhancement. Because order can matter in pipelines if multiple share the same priority, I propose to use the default order from Python sorted() function that should be a quite natural choice.