docs scanner manually generates json blobs

Hand-generating json is terrible and will fail in weird and wonderful ways. One such way I have is with:

$ gst-inspect-1.0 gareus-org-oss-lv2-spectra-Mono
...
  window              : Window Function
                        flags: readable, writable, controllable
                        Enum "gareus-org-oss-lv2-spectra-Monowindow" Default: 0, "Hann"
                           (0): Hann             - Hann
                           (1): Hamming          - Hamming
                           (2): Nuttall          - Nuttall
                           (3): ^\^A               - ^\^A
                           (4): 4                - 4
                           (5): Flat top         - Flat top

Which results in invalid json being generated (mismatching {,} braces I think)