Merge new doc from 'reconverge' into 'fix_rlc'

...ns_v2/20181110120202_create_childtable_user_join_group.js

.../20181110120303_create_childtable_group_join_metagroup.js

.../20181110120404_create_childtable_group_coauthor_event.js

db/migrations_v2/readme.txt

db/seeds/00_special_groups.js

db/seeds/01_dummy_groups.js

db/seeds/02_dummy_metagroups.js

db/seeds/03_dummy_metagroup_memberships.js

db/seeds/04_dummy_announcements.js

db/seeds/05_dummy_events.js

db/seeds/06_dummy_private_posts.js

db/seeds/07_dummy_requests.js

db/seeds_v1/01_create_groups.js

db/seeds_v1/02_make_metagroups.js

db/seeds_v1/03_make_requests.js

db/seeds_v1/04_make_posts.js

db/seeds_v1/05_metagroup_membership.js

db/seeds_v1/06_taken_rights.js

db/seeds_v1/07_make_event.js

notes/CONTRIBUTING.md