Development Guide

Hi Canonical community,

I try to understand the codebase and try to build the microcloud for local development purpose. Unfortunately, I didn't found any development guide, so I try to explore around. I found there is a makefile, so i guess I will start from there, when I try to `make build`, it show it unable to find `schema.ErrGracefulAbort`. I believe `ErrGracefulAbort` is no longer found in repo https://github.com/canonical/lxd

```
../../go/pkg/mod/github.com/canonical/microcluster/v2@v2.1.0/internal/db/update/schema.go:154:35: undefined: schema.ErrGracefulAbort
../../go/pkg/mod/github.com/canonical/microcluster/v2@v2.1.0/internal/db/update/schema.go:158:21: undefined: schema.ErrGracefulAbort
../../go/pkg/mod/github.com/canonical/microcluster/v2@v2.1.0/internal/db/update/schema.go:180:26: undefined: schema.ErrGracefulAbort
```

And I realize it need some dependency in the environment as well to build which i not configure correctly which result in
```
../../go/pkg/mod/github.com/canonical/go-dqlite/v2@v2.0.0/internal/bindings/server.go:265:11: could not determine what C.dqlite_node_describe_last_entry refers to
../../go/pkg/mod/github.com/canonical/go-dqlite/v2@v2.0.0/internal/bindings/server.go:190:11: could not determine what C.dqlite_node_enable_disk_mode refers to
```

If there is any written guidance I can refer to or the community has any recommendation for me to start contribute.