Automatic command chaining: Cmd -> Cmd -> Msg

**Is your feature request related to a problem? Please describe.**
No.

**Describe the solution you'd like**
```go
switch msg := msg.(type) {
case tea.Cmd:
return m, msg
}
```

**Describe alternatives you've considered**
N/A

**Additional context**
I have a Cmd which produces other Cmds:
```go

func (m *Model) Create(name string) tea.Cmd {
return func() tea.Msg {
if !isAlphaNumeric(name) {
return tea.Println("Only alphanumeric characters are allowed.")
}

var game db.Game
m.app.db.Where("name = ?", name).First(&game)
if game.ID != 0 {
return tea.Printf("Game %q already exists. Please choose another name.", name)
}

game = db.Game{
Name: name,
}
if err := m.app.db.Create(&game).Error; err != nil {
slog.Error("Failed to create game", "err", err.Error())
}
return tea.Printf("Game created!")
}
}
```

It will be cool it cmds can produce other cmds.

This is easily solvable via:

```go
switch msg := msg.(type) {
case tea.Cmd:
return m, msg
}
```

But as Msg == any it took me some time to understand why nothing is printed. What about adding this as default behavior?