ls *.woff2 *.woff *.ttf *.otf gave me the following list:

Alvania.ttf
Ambidexter_Regular.otf
Archive.ttf
Arturito.ttf
Avara_R.woff2
Avara_RI.woff2
AvenirNext-Bold.woff2
AvenirNext-BoldItalic.woff2
AvenirNext-Demi.woff2
AvenirNext-DemiItalic.woff2
AvenirNext-Heavy.woff2
AvenirNext-HeavyItalic.woff2
AvenirNext-Italic.woff2
AvenirNext-Light.woff2
AvenirNext-LightItalic.woff2
AvenirNext-Medium.woff2
AvenirNext-MediumItalic.woff2
AvenirNext-Regular.woff2
AvenirNext-Thin.woff2
AvenirNext-ThinItalic.woff2
AvenirNext-UltraLight.woff2
AvenirNext-UltraLightIt.woff2
Axis.otf
Baldur.ttf
Bizon.otf
Blankenburg.ttf
Blazed.ttf
Bondi.otf
Boston.ttf
CATReporter.ttf
Canobis-Regular.otf
Cherish-Regular.ttf
ComicTantrum.otf
Commune-Nuit_Debout_Pochoir_web.woff2
Commune-Nuit_Debout_web.woff2
Disket_B.ttf
Disket_R.ttf
Docker_L.ttf
Docker_R.ttf
DonJose.otf
Doppelganger.otf
EBGaramond08_R.woff
EBGaramond08_RI.woff
EBGaramond12_R.woff
EBGaramond12_RI.woff
Envy Code R.ttf
FEAST_OF_FLESH.ttf
FEAST_OF_FLESH_Italic.ttf
Forta.woff2
GrobeDeutschmeister.ttf
GulfsDisplay-Condensed.ttf
GulfsDisplay-CondensedItalic.ttf
GulfsDisplay-Expanded.ttf
GulfsDisplay-ExpandedItalic.ttf
GulfsDisplay-ExtraExpanded.ttf
GulfsDisplay-ExtraExpandedItalic.ttf
GulfsDisplay-Normal.ttf
GulfsDisplay-NormalItalic.ttf
GulfsDisplay-SemiCondensed.ttf
GulfsDisplay-SemiCondensedItalic.ttf
GulfsDisplay-SemiExpanded.ttf
GulfsDisplay-SemiExpandedItalic.ttf
GulfsDisplay-Variable.ttf
GulfsDisplayItalic-Variable.ttf
Hamlet-Cicero12.otf
Hamlet-Tertia18.otf
Harbinger.otf
HermanoAlto Round.ttf
HermanoAlto Stamp.ttf
Hermit-Bold.otf
Hermit-BoldItalic.otf
Hermit-Light.otf
Hermit-LightItalic.otf
Hermit-Regular.otf
Hermit-RegularItalic.otf
Humane-Bold.ttf
Humane-ExtraLight.ttf
Humane-Light.ttf
Humane-Medium.ttf
Humane-Regular.ttf
Humane-SemiBold.ttf
Humane-Thin.ttf
Imposible_outline.ttf
Inter-Black.woff2
Inter-BlackItalic.woff2
Inter-Bold.woff2
Inter-BoldItalic.woff2
Inter-ExtraBold.woff2
Inter-ExtraBoldItalic.woff2
Inter-ExtraLight.woff2
Inter-ExtraLightItalic.woff2
Inter-Italic.woff2
Inter-Light.woff2
Inter-LightItalic.woff2
Inter-Medium.woff2
Inter-MediumItalic.woff2
Inter-Regular.woff2
Inter-SemiBold.woff2
Inter-SemiBoldItalic.woff2
Inter-Thin.woff2
Inter-ThinItalic.woff2
Inter-italic.var.woff2
Inter-roman.var.woff2
Kielo.otf
LEMONMILK-Bold.otf
LEMONMILK-BoldItalic.otf
LEMONMILK-Light.otf
LEMONMILK-LightItalic.otf
LEMONMILK-Medium.otf
LEMONMILK-MediumItalic.otf
LEMONMILK-Regular.otf
LEMONMILK-RegularItalic.otf
LaborUnion-Regular.otf
LaborUnion-Small.otf
LeagueGothic-CondensedItalic.otf
LeagueGothic-CondensedRegular.otf
LeagueGothic-Italic.otf
LeagueGothic-Regular.otf
Leiko.otf
LinLibertine_R.otf
LinLibertine_RB.otf
LinLibertine_RBI.otf
LinLibertine_RI.otf
LouisGeorgeCafe.ttf
LouisGeorgeCafeBold.ttf
LouisGeorgeCafeBoldItalic.ttf
LouisGeorgeCafeItalic.ttf
LouisGeorgeCafeLight.ttf
LouisGeorgeCafeLightItalic.ttf
MDTall.ttf
Mamenchisa.otf
MammutCAT.ttf
Margaret.otf
MarvinVisionsBig-Bold.woff2
Mersad Black.ttf
Mersad Bold.ttf
Mersad ExtraBold.ttf
Mersad ExtraLight.ttf
Mersad Light.ttf
Mersad Medium.ttf
Mersad Regular.ttf
Mersad SemiBold.ttf
Mersad Thin.ttf
MilkCarton.otf
Misto.otf
MonTrappist-Black.otf
Monolith.otf
Montreau.otf
NIM.ttf
Newake-Font-Demo.otf
OverpassMono_B.woff2
OverpassMono_R.woff2
Overpass_B.woff2
Overpass_BB.woff2
Overpass_BBI.woff2
Overpass_BI.woff2
Overpass_L.woff2
Overpass_LI.woff2
Overpass_R.woff2
Overpass_RI.woff2
Planck.otf
Quakep.otf
REFUSE.otf
RESIN.woff
Rafigen Demo.ttf
RemboyRegular.ttf
Ribes-Black.otf
Roboto_B.ttf
Roboto_BB.ttf
Roboto_BBI.ttf
Roboto_BI.ttf
Roboto_L.ttf
Roboto_LI.ttf
Roboto_R.ttf
Roboto_RI.ttf
RousseauDeco.ttf
SaintRegus-SemiBold.otf
SaintRegus-SemiBoldCondensed.otf
SaintRegus-SemiBoldExpanded.otf
SonderRegular.otf
Surfing_Capital.ttf
Theater.otf
Tintin.ttf
Trappist.otf
Tropikal.otf
Ustroke.ttf
Vercetti-Regular.otf
Vollkorn_B.woff2
Vollkorn_BB.woff2
Vollkorn_BBI.woff2
Vollkorn_BI.woff2
Vollkorn_L.woff2
Vollkorn_LI.woff2
Vollkorn_R.woff2
Vollkorn_RI.woff2
VolumeDealer.otf
Wavehaus-128Bold.otf
Wavehaus-158ExtraBold.otf
Wavehaus-28Thin.otf
Wavehaus-42Light.otf
Wavehaus-66Book.otf
Wavehaus-95SemiBold.otf
Werbedeutsch.otf
banco.ttf
mononoki-Bold.ttf
mononoki-BoldItalic.ttf
mononoki-Italic.ttf
mononoki-Regular.ttf
theboldfont.ttf

Write a JSON file with this style:

[
    "vollkorn" : {
        "name": "Vollkorn",
        "weights" : {
            "400": "Vollkorn_R.woff2",
            "400i": "Vollkorn_RI.woff2",
            "700": "Vollkorn_B.woff2",
            "700i": "Vollkorn_BI.woff2"
            ...
        },
        "tags" : ["serif", "google-fonts"],
        "license" : "SIL Open Font License, 1.1",
    }
]