docs: Tweaks to welcome.md section about changing default homepage
docs: Tweaks to welcome.md section about changing default homepage

code-computerlove/slate,CodeRichardJohnston/slate-demo,code-computerlove/quarry,code-computerlove/slate-cli,cartridge/cartridge,cartridge/cartridge-cli,CodeRichardJohnston/slate-demo,code-computerlove/slate