* [BREAKING] refactor: Normalize WorkflowBuilder APIs
* "partitioner" => "assigner"
* normalize ordering so sources always to the left of targets for edges
* normalize parameter ordering so sources and targets are always first arguments
* remove `params` (users should use collection expressions instead)
* refactor: Align name with Python
* Adding more test for workflow vizualization.
* Improving README for sample.
* More cleanup.
* Removing rendering of workflow visualization and adding basic support for mermaid format.
* Adding basic mermaid tests.
* Improving sample. Switching to another branch.
* About to merge from main.
* Formatting.
* More fromatting.
* Removng uneeded call to ToUpper.
* Adding README.
* Moving samples under workflow to workflows.
* Removing uneeded README for map-reduce sample.