docs: fix typos and small text improvements

docs/dev/hardware.rst

docs/dev/site_library.rst

docs/dev/wan.rst

docs/dev/web/controller.rst

docs/features/autoupdater.rst

docs/features/configmode.rst

docs/features/multidomain.rst

docs/features/private-wlan.rst

docs/user/getting_started.rst

docs/user/site.rst

docs/user/x86.rst