docs: Add documentation for Services and Tasks

[stefanorosanelli]

This commit introduces a new markdown file, services_and_tasks.md, which explains the architecture and usage of Services and Tasks within the Brevia framework.

The documentation covers:

• The role and implementation of BaseService, including how to create custom services.
• The role and implementation of BaseAnalysisTask, including how to create custom tasks and their interaction with LangChain.
• The relationship and typical workflow between Services and Tasks.
• Guidance on customization, with references to existing tutorials and prompt management.

The mkdocs.yml file has also been updated to include this new page in the site navigation under "Services and Tasks".

[Copilot]

Pull Request Overview

Adds comprehensive documentation for the Services and Tasks architecture in the Brevia framework and updates site navigation.

• Introduces services_and_tasks.md detailing BaseService, BaseAnalysisTask, typical workflows, and customization guidance.
• Updates mkdocs.yml to register the new documentation page in the site navigation.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
mkdocs.yml	Added “Services and Tasks” to the navigation menu
docs/services_and_tasks.md	New documentation on Services, Tasks, and workflows

Comments suppressed due to low confidence (1)

mkdocs.yml:59

• [nitpick] Indentation here is inconsistent with the surrounding nav entries (which use 4 spaces). Adjust to match the existing format so the page appears correctly under the parent section.

  - Services and Tasks: services_and_tasks.md

[Copilot]

The comment contradicts the earlier note about validation printing and returning False. Clarify whether run raises a ValueError on validation failure and update the example comments to reflect the actual behavior.

Suggested change

	# The run method would raise a ValueError if validate returns False
	# print(f"Running with invalid payload (missing key): {invalid_payload_missing}")
	# try:
	# service.run(invalid_payload_missing)
	# except ValueError as e:
	# print(f"Error: {e}") # Similar to above
	# The run method does not raise a ValueError; it relies on validate to handle errors.
	# print(f"Running with invalid payload (missing key): {invalid_payload_missing}")
	# try:
	# service.run(invalid_payload_missing)
	# except ValueError as e:
	# print(f"Error: {e}") # Similar to above: validate prints the error and returns False, but no exception is raised.

[Copilot]

[nitpick] It’s recommended to call super().__init__() within the constructor to ensure any initialization in BaseAnalysisTask is properly executed.

Suggested change

	def __init__(self, text: str, custom_prompt_template: str | None = None):
	def __init__(self, text: str, custom_prompt_template: str | None = None):
	super().__init__() # Ensure proper initialization of the base class