Fix Context.map() parameter documentation for Python

[yaythomas]

The documentation shows incorrect parameter count for the map() function in Python.

Current documentation: Shows 2 parameters for map function

Actual implementation: Type checker requires 4 parameters: (ctx, config, index, all_inputs)

Affected documentation: Examples showing map function usage, particularly in the context of invoking external service modules.

Action needed:

1. Update all Python map examples to show correct 4-parameter signature
2. Add clear documentation of each parameter's purpose
3. Ensure consistency across all map-related examples

Reference: Check docs/core/map.md for current parameter documentation.

[yaythomas]

Actual is

  Callable[[DurableContext, U, int, Sequence[U]], T]
  # i.e.: (ctx, item, index, items)