Seed-database.md

+Database seeds are managed by [seedbank](https://github.com/james2m/seedbank) in the standard `db/seed` directory.
+
+`chouette-core` only provides development seeds. Sub-projects should use the environment mechanism provided by seedbank to complete and provide their own data.
+
+You can seed the database by running: `rake db:seed`
+
+## Create a specific seed
+
+You can use helpers provided by `seed_helpers`:
+
+```ruby
+require_relative 'seed_helpers'
+
+organisation = Organisation.seed_by(code: "acmee") do |o|
+  o.name = 'ACMEE Organisation'
+end
+
+stop_area_referential = StopAreaReferential.seed_by(name: "ACMEE StopPoints") do |r|
+  r.objectid_format = "netex"
+  r.add_member organisation, owner: true
+end
+
+line_referential = LineReferential.seed_by(name: "ACMEE Lines") do |r|
+  r.objectid_format = "netex"
+  r.add_member organisation, owner: true
+end
+
+workgroup = Workgroup.seed_by(name: "ACMEE Workgroup") do |w|
+  w.line_referential      = line_referential
+  w.stop_area_referential = stop_area_referential
+end
+```