Updates to the documentation site (livewire-powergrid.com and subdomains)

[luanfreitasdev]

Hello everybody! The subdomains of the livewire-powergrid website are no longer available. Therefore, all the old links no longer worked.

Documentation before v5 (latest) will only be available on GitHub,

3x: https://github.com/Power-Components/powergrid-doc/tree/3x/docs
4x: https://github.com/Power-Components/powergrid-doc/tree/4x/docs

latest: livewire-powergrid.com