misc: remove ring-client-gnome and Ring occurences

developer/jami-concepts/account-management.md

developer/jami-concepts/banned-contacts.md

developer/jami-concepts/contact-management.md

developer/jami-concepts/file-transfer.md

developer/jami-concepts/jami-identifiers.md

developer/processes/release-process.md

jami-extensions/how-it-works.md

jami-extensions/how-to-build.md

user/bug-report-guide.md

user/jami-distributed-network.md