qmk/modules/getreuer/sentence_case/qmk_module.json

{
    "module_name": "Sentence Case",
    "maintainer": "getreuer",
    "keycodes": [
        {"key": "SENTENCE_CASE_ON"},
        {"key": "SENTENCE_CASE_OFF"},
        {"key": "SENTENCE_CASE_TOGGLE"}
    ]
}