restructure few sections and starting points

_config.yml

_data/apidefinitions/broadcast_ops.yml

_data/apidefinitions/broadcast_ops_communities.yml

_data/nav.yml

_introduction/web3.md

_introduction/welcome.md

_introduction/workflow.md

_quickstart/authentication.md

_quickstart/choose_library.md

_quickstart/fetch_broadcast.md

_quickstart/hive_full_nodes.md

_quickstart/testnet.md

_resources/hivesigner_libs.md

_services/hivesigner.md

_tutorials-javascript/hivesigner.md

images/hive-dev-structure.png