Issue with schema.resolvers.go content being overwritten after model update

After completing the graph server setup based on the official demo, I wanted to update the model to complete the custom functions, but encountered several issues:

1. To completely regenerate, you need to delete basic files such as generated.go, schema.resolvers.go, and leave only the dependent configurations and models.

2. Due to my desire to retain the previous schema.resolvers.go content, which includes new features, when I regenerate it, the content in schema.resolvers.go will be reset. If there are enough features, this will become a serious problem that I will face every time I update the model.

Based on the above two points, I hope to request a solution, which is how to integrate gqlgen into my project, so that I only need to focus on incremental updates of the model and schema. resolvers. go. Other parts, such as generated. go, should not be the focus of every user updating the model or graphqls file.

### versions
- `go run github.com/99designs/gqlgen version`?
- 0.17.31
- `go version`?
- 1.20