### What needs to get done * Split the [reference documentation](https://canonical-snapcraft.readthedocs-hosted.com/en/latest/reference/architectures/#supported-architectures) about supported architectures by base. * The difference between bases is that support for `i386` and `powerpc` (not `ppc64el`) was dropped in `core22` and newer bases. * "Supported locally" and "supported by launchpad" are the same for core22 and newer bases. For core20, "powerpc" is locally supported. * Update outdated docs or point them to read the docs: * https://snapcraft.io/docs/reference-architectures#supported-architectures * https://snapcraft.io/docs/build-from-github ### Why it needs to get done To make it clear which architectures are supported for which bases.