feat: move tree to root

[caarlos0]

closes #339
closes #341

[meowgorithm]

If you don't mind, going to look at a few last things today before we merge this one.

[bashbunni]

Hey @meowgorithm any changes on this one?

[meowgorithm]

Let’s get the tree examples back in as well — I'm looking at stuff now.

[bashbunni]

@meowgorithm kk no rush. Just added the examples back

[meowgorithm]

Feeling good! Let's get this done ⚡️

[bashbunni]

Removed JoinVertical from the final rendered element as it was writing unstyled whitespace to the final string. It does that by design to appropriately align elements in the block, but because it doesn't have access to the style, the whitespace can't be rendered. That said, I haven't seen this issue outside of the tree examples, so it's not pressing.

If we did want to fix this we could replace this whitespace rendering with calling Align on the style which can render the whitespace properly or fix this with our compositor in a future version of lipgloss

[bashbunni]

TODO before merge

• tidy godoc (some tree docs mention list)
• tidy godoc - opened a PR against this branch with improvements
• show an example of unique styling of the root element (this might be broken)
• add tree info to README.md

[bashbunni]

I thought the lipgloss root styling might be broken because if we do

ItemStyleFunc(func(children tree.Children, i int) lipgloss.Style {
    if children.At(i).Value() == "Nyx" {                          
        return itemStyle.Background(lipgloss.Color("#04B575"))    
    }                                                             
    return itemStyle                                              
})                                                                

we get

%!v(PANIC=String method: runtime error: invalid memory address or nil pointer dereference)

because when we're on the root item, it's children.At(-1) which returns nil, then we attempt to call Value() on it.

As-is we will always need to do a root value check in ItemStyleFunc to avoid this...

[bashbunni]

We might even want to see about separating out RootStyle from ItemStyle 💭

[caarlos0]

We might even want to see about separating out RootStyle from ItemStyle 💭

i think that makes more sense yes