Initial v0 of docs-assembler repos build-all command.

[Mpdreamz]

• Add docs-assembler repos build-all
• Explicit username if github token is provided
• Build narritive docs to root

[Copilot]

Pull Request Overview

This PR introduces the "assembler build" feature to support building all documentation repositories, explicitly handles GitHub tokens for repository origins, and builds narrative docs to the root directory.

• Added an AssemblerBuilder to manage the build-all process with improved exception handling.
• Refactored repository sourcing by replacing the legacy RepositoryCloner with a new RepositoryCheckoutProvider.
• Enhanced configuration deserialization to apply default repository values.

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/docs-assembler/Building/AssemblerBuilder.cs	Introduces the build-all functionality and enhanced exception handling.
src/docs-assembler/Sourcing/RepositorySourcesFetcher.cs	Refactors repository sourcing and checkout aggregation.
src/docs-assembler/Sourcing/Checkout.cs	Provides a new record for encapsulating checkout details.
src/docs-assembler/Configuration/Repository.cs	Defines repository configurations with defaults.
src/docs-assembler/Configuration/AssemblyConfiguration.cs	Updates deserialization with repository defaults based on the environment.
src/docs-assembler/Cli/RepositoryCommands.cs	Updates CLI commands to incorporate the new build-all and clone-all behavior.
src/Elastic.Markdown/BuildContext.cs	Adjusts the AllowIndexing property for proper URL path prefixing.
src/docs-builder/Cli/Commands.cs	Corrects the AllowIndexing assignment logic.
src/docs-assembler/AssembleContext.cs	Introduces a CheckoutDirectory property to support checkouts.
src/docs-assembler/Sourcing/RepositoryCloner.cs	Removes the legacy repository cloner in favor of the RepositoryCheckoutProvider.

Comments suppressed due to low confidence (1)

src/docs-assembler/Building/AssemblerBuilder.cs:31

• Consider replacing 'Console.WriteLine(e);' with '_logger.LogError(e, "An error occurred while building checkout.")' to ensure consistent logging throughout the application.

Console.WriteLine(e);

[Copilot]

Replace the array literal '[Configuration.Narrative]' with a valid array initialization such as 'new[] { Configuration.Narrative }' to fix the syntax.

Suggested change

	var repositories = Configuration.ReferenceRepositories.Values.Concat<Repository>([Configuration.Narrative]);
	var repositories = Configuration.ReferenceRepositories.Values.Concat<Repository>(new[] { Configuration.Narrative });