Designing boards with plug-n-play connectivity is a snap, with STEMMA connectors. Here's a pack of 10 of our favorite 2mm pitch connector - the JST PH 4 pin. These are the vertical style.
You can use these with any of our JST PH 4 / STEMMA cables. They're not STEMMA QT compatible (those use the smaller JST SH). However, you can fit Seeed Grove connectors into JST PH which is pretty handy.