chore: add licenses

application/source/commands/01_definitions.go

application/source/commands/02_command.go

application/source/commands/03_errors.go

application/source/commands/07_execute.go

application/source/commands/08_document.go

application/source/commands/08_document_add.go

application/source/commands/08_document_html.go

application/source/commands/08_document_pdf.go

application/source/commands/08_version.go

application/source/commands/09_server.go

application/source/commands/09_server_serve.go

application/source/document/build.go

application/source/document/create.go

application/source/document/document.go

application/source/document/errors.go

application/source/document/files.go

application/source/document/html.go

application/source/document/latex_mapping.go

application/source/document/pandoc.go

application/source/document/pdf.go