Change FlowParams to PipelineContext

As the POC iterated, we settled on capturing runtime parameters in
a PipelineContext object available to all blocks in the pipeline.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Author: markmc

Diff for: docs/sdg/sdg-flow-yaml.md

@@ -82,17 +82,16 @@ def parse_custom_flow(content):
         logger.warning("The custom flow file may have new features that will be ignored.")
 ```
 
-### Flow Params
+### Pipeline Context
 
-The following parameters are supplied to a Flow constructor and used by the render() method:
+The following runtime parameters will no longer be part of the pipeline configuration definition and instead available to blocks via a `PipelineContext` object:
 
 - client - an OpenAI completions API client for talking to the teacher model via the serving backend (i.e. llama-cpp or vLLM)
 - model_family - e.g. mixtral or merlinite
 - model_id - a path name for the specific teacher model being used
 - num_instructions_to_generate - how many samples to generate
-- batched - whether the model serving backend supports batched mode
 
-For now, we assume that the `Block` classes know how to use these parameters and there is no need to use any sort of templating in the custom flows that could use these parameters.
+For now, we assume there is no need to do any sort of templating in the custom pipelines based on these runtime parameters.
 
 ### Model Prompts