[Nacara.Layout.Standard] Ability to customize the footer

[MangelMaxime]

Allow the user to provide a FooterConfig object in order to customize the footer to its needs

type CopyrightConfig =
    {
        StartDate : string
        Suffix : string option
    }

type SiteMapSectionItem =
    {
        Text : string
        Icon : string option
        Url : string
    }

type SiteMapSection =
    {
        Title : string
        Items : SiteMapSectionItem list
    }

[<NoComparison>]
type FooterConfig =
    {
        CenterText : ReactElement option
        Copyright : CopyrightConfig option
        SiteMap : SiteMapSection list
    }

It is based on the footer created for Elmish documentations: