Use url_for in documentation templates

templates/documentation-configuration-todomails.html

templates/documentation-configuration-types.html

templates/documentation-configuration.html

templates/documentation-sessionmanagement-plan.html

templates/documentation-sessionmanagement-tracking.html

templates/documentation-sessionmanagement-write.html

templates/documentation-sessionmanagement.html

templates/documentation-syntax-internal.html

templates/documentation-syntax-meta.html

templates/documentation-syntax-tags.html

templates/documentation-syntax-top.html

templates/documentation-syntax.html

templates/documentation.html