📘 DOCS-#119: Fix documentation gaps — incorrect references, missing parameters, outdated attributes

[FernandoCelmer]

Description

• docs/nav/reference/context.md: Removed non-existent members (result_task, result_context, result_storage)
• docs/nav/reference/config.md: Fixed members to match actual class (storage, notify, log, api)
• docs/nav/reference/task-instance.md: Fixed _error to _errors, added retry_count
• docs/nav/reference/dotflow.md: Added missing result() method
• docs/nav/reference/task-builder.md: Added missing schema() and result() methods
• docs/nav/reference/workflow.md: Added sequential_group method
• dotflow/core/action.py: Fixed backoff docstring type from int to bool, added description
• dotflow/core/config.py: Fixed log docstring copy-paste error
• dotflow/core/dotflow.py: Documented workflow_id parameter
• dotflow/core/workflow.py: Documented resume parameter

Motivation and Context

Documentation review found incorrect member references, missing parameters, and outdated attribute names across reference pages and docstrings.

Closes #119

Types of changes

• Bug fix (change that fixes an issue)
• Documentation

Checklist

• I have performed a self-review of my own code
• I have added tests that prove my fix is effective or that my feature works
• I have updated the CHANGELOG
• I have updated the documentation accordingly