Rewrite at compileTime

Get mad with Macros. Use Nim macros to write SQL.

Example:

```nim
update User:
  @set:
    email = "new@example.com"
    status = true
  where(email == "old@example.com")
```

```sql
UPDATE users SET email = 'new@example.com', status = true WHERE email = 'old@example.com'
```