quick includes from local folders (resolves #904)

[alaindresse]

This PR (resolves #904 ) allows for antora includes resource ID like include::module:family$filename[] to be resolved directly without relying on an antora configuration.

This is enabled only if the setting antora.enableAntoraSupport is false (to avoid conflicts with proper management of resource IDs) and if antora.enableLocalIncludes is true (which I set at true by default in this PR).

Changes are:

• Create an IncludeProcessor to handle the targetted resourceIds,
• Register that includeProcessor
• Add the new antora.enableLocalIncludes setting
• Document the new antora.enableLocalIncludes setting (thank you Copilot for translation in languages I don't know)

[alaindresse]

Rejected because this is essentially a workaround and should be replaced by a proper solution.