- [X] Prepare backlog
  - [X] Install 'db dependencies
  - [X] Add db namespace in dev/test routine
Refactor - Rename function
  - [X] Create an org-trello database
  - [X] Replace serialization steps (file writing) with the database writing implementation
Refactor - rename internal functions
Refactor - format code
Add some functions
Fix error at db initialization
- [X] Replace the deserialization steps with the database reading implementation
  - [X] Simplify web admin page listing the remaining entities to make action on
  - [X] Native nothing to do - Serialize database when org-trello is shut down (per buffer)
  - [X] Native nothing to do - Deserialize database when org-trello is started and merge with the existing one
  - [X] Clean all the current running actions
  - [X] Clean the current running action
 - [X] Fix some bad behaviors (bad order in db and http requests, write
   to disk at every actions in db, ...)
  - [X] Initialize the database
  - [X] Make some refactoring
  - [X] Serialize database when org-trello is shut down (per buffer)
- [X] Update README-dev.md about the new db namespace