Steps to add a Field to Entities

1. Create a migration
   cd backend && diesel migration generate my_new_migration
   This will create up.sql and down.sql inside a new migration folder under /backend/migrations/
up.sql should create all necessary tables, columns, constraints as well as modify data if necessary
   down.sql should undo all changes from up.sql

2. Run the migration
   make migrations
   During development you can run make migrations-redo to run down.sql and up.sql of the most recent migration

3. Add new field to Entity
   e.g. extend the Plants entity in entity.rs

4. (Optional) Update the schema patch
   If you see an error message similar to error applying hunk #2, you will have to update schema.patch

5. Add field to DTOs (where applicable)
   e.g. extend PlantsSummaryDto in dto.rs

6. Update usages and trait implementations of DTOs (where applicable)
   e.g. implementation of the From Trait for PlantsSummaryDto in plants_impl.rs
   IMPORTANT: The order of the fields in the DTOs and corresponding entity must be the same as in the generated schema.rs.

7. Update database schema documentation
   Review the documentation under /doc/database/schemata and make the necessary changes.

8. Extend API documentation
   Review the swagger API documentation under http://localhost:8080/doc/api/swagger/ui/
   For better understanding of the API endpoints that uses the modified DTOs, consider adding an #[schema(example = "...")] attribute macro to the DTO
   For example:

pub struct TimelineDto {
    #[schema(example = "{ \"2020\": { \"additions\": 7, \"removals\": 7 } }")]
    pub years: HashMap<String, TimelineEntryDto>,
    [...]
}