Here is a list of all documented files with brief descriptions:

include
units
acceleration.h	Units representing acceleration values
angle.h
angular_acceleration.h	Units representing angular acceleration values
angular_jerk.h	Units representing angular jerk values
angular_velocity.h	Units representing angular velocity values
area.h	Units representing area values
capacitance.h	Units representing capacitance values
charge.h	Units representing charge values
concentration.h	Units representing concentration values
conductance.h	Units representing conductance values
core.h	unit, dimensional analysis, generic cmath functions, traits (not dimension-specific), and what they're implemented with (conversion_factor, unit manipulators, etc.)
current.h	Units representing current values
data.h	Units representing data values
data_transfer_rate.h	Units representing data transfer rate values
density.h	Units representing density values
eigen.h	Optional, dependency-free interoperability between units and the Eigen linear-algebra library
energy.h	Units representing energy values
energy_density.h	Units representing energy density values
force.h	Units representing force values
frequency.h	Units representing frequency values
illuminance.h	Units representing illuminance values
impedance.h	Units representing impedance values
inductance.h	Units representing inductance values
irradiance.h	Units representing irradiance values
jerk.h	Units representing jerk values
kind.h	Opt-in affine wrappers: units::absolute<U> (a point on a scale, carries the unit's datum) and units::delta<U> (an offset-free amount)
length.h	Units representing length values
luminance.h	Units representing luminance values
luminous_flux.h	Units representing luminous flux values
luminous_intensity.h	Units representing luminous intensity values
magnetic_field_strength.h	Units representing magnetic field strength values
magnetic_flux.h	Units representing magnetic flux values
mass.h	Units representing mass values
power.h	Units representing power values
pressure.h	Units representing angle values
radiance.h	Units representing radiance values
radiant_intensity.h	Units representing radiant intensity values
radiation.h	Units representing radiation values
serialization.h	Self-describing binary serialization of quantities
solid_angle.h	Units representing solid angle values
spectral_flux.h	Units representing spectral flux values
spectral_intensity.h	Units representing spectral intensity values
spectral_irradiance.h	Units representing spectral irradiance values
spectral_radiance.h	Units representing spectral radiance values
substance.h	Units representing amount of substance values
substance_concentration.h	Units representing substance concentration values
substance_mass.h	Units representing substance mass values
temperature.h	Units representing temperature values
time.h	Units representing time values
torque.h	Units representing torque values
velocity.h	Units representing velocity values
viscosity.h	Units representing dynamic and kinematic viscosity values
voltage.h	Units representing voltage values
volume.h	Units representing volume values
volume_flow_rate.h	Units representing volumetric flow rate values
units.h	Complete implementation of units - a compile-time, header-only, unit conversion library built on c++23 with no dependencies