Update local dev setup guide

[alienxp03]

Just trying out the repo earlier. I have some suggestions.

• Current setup is mainly for devcontainer and VS Code. I'm using Neovim so the flow is a bit different. Thinking if we can have a separate section for non-devcontainer setup? Something more generic. Minimal change most likely, so might not need to mantain two different version. Like right now, database.yml is hardcoded to devcontainer setup. So moving it to something like below can help the setup to be more generic.

default: &default
  host: <%= ENV["POSTGRES_HOST"] %>
  username: <%= ENV["POSTGRES_USER"] %>
  password: <%= ENV["POSTGRES_PASSWORD"] %>
  database: <%= "petakopi_#{Rails.env}" %>
  adapter: postgis
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default

test:
  <<: *default

production:
  <<: *default

• Another question. I noticed I can seed some data using seeder:states and seeder:regions but it looks like the data is not public (/data is in .gitginore). Any suggestion on how can I proceed? And is there a way to seed some existing data into the development db as well?