earthsciencekit 0.2.0

• First release on PyPI, with the git history on GitHub, CI, tag-driven
  releases (release.yml), docs hosted on GitHub Pages (docs.yml), a mypy
  step in CI, JupyterLite buttons on the gallery and a Colab quickstart
  notebook (ROADMAP item 1).
• New geophysics domain (ROADMAP item 6): gravity anomalies and reductions,
  normal gravity, Clairaut's theorem and the flattening, satellite J2, Stokes's
  geoid kernel, the axial dipole and zonal Gauss coefficients, field elements,
  virtual geomagnetic poles, magnetic anomalies of reversed blocks, the dynamo
  scales, Love numbers and GRACE equivalent water: 30 algebraic models and the
  dynamic simulate_rikitake_dynamo. Its history is a dated chronology of 16
  breakthroughs, from Gilbert's magnetic Earth (1600) to GRACE (2002), each with
  its own executed example.
• New units m/s^2, mGal, T and nT.
• New volcanology domain (ROADMAP item 7): radioactive decay and the age
  equation, radiocarbon, Pb-Pb ages, the U-Pb concordia and the isochron,
  Rayleigh fractionation and delta values, fractional and equilibrium
  crystallization, lattice-strain partitioning, the oxygen-isotope
  thermometer, Arrhenius and Shaw viscosity, water solubility, dike ascent,
  the Mogi source, plume and eruption-column heights and the VEI: 23
  algebraic models and the dynamic simulate_eruption_column. Its history is
  a dated chronology of 17 breakthroughs, from Rayleigh's fractional
  distillation (1896) to the Volcanic Explosivity Index (1982), each with its
  own executed example.
• New units kyr, Ma, Ga and GPa; new constants AVOGADRO,
  LAMBDA_U238, LAMBDA_U235, U238_U235 and LIBBY_MEAN_LIFE.
• Family layout: each domain is a package of systems/<topic>.py modules with
  core/, visualizers/ and tests/; constants and units are packages and
  the cross-cutting tests moved from tests/ to earthsciencekit/tests/. Every
  public import path, such as from earthsciencekit.climate import simulate_one_box,
  is unchanged.
• plate_tectonics history is a dated chronology of 16 breakthroughs, from Euler's
  rotation theorem (1776) to NUVEL-1 (1990), each with its own executed example;
  the three shared plate_tectonics gallery scripts are removed.
• New plate_tectonics models: mantle_rayleigh_number, flexural_deflection,
  hotspot_age, ocean_depth and compose_euler_vectors.
• seismology history is a dated chronology of 16 breakthroughs, from Poisson's
  two elastic waves (1829) to PREM (1981), each with its own executed example;
  the three shared seismology gallery scripts are removed.
• New seismology models: rayleigh_wave_speed, head_wave_travel_time,
  crossover_distance, love_wave_angular_frequency, ray_parameter,
  local_magnitude and vertical_travel_time.
• atmosphere history is a dated chronology of 16 breakthroughs, from Torricelli's
  barometer (1643) to the ENIAC forecast (1950), each with its own executed example;
  the three shared atmosphere gallery scripts are removed.
• New atmosphere models: barometer_column_height, two_layer_temperature,
  richardson_number, surface_pressure_tendency, rossby_wave_speed and the
  dynamic simulate_barotropic_vorticity.
• climate history is a dated chronology of 16 breakthroughs, from Fourier's
  greenhouse (1824) to the sea-level budget (2005), each with its own executed
  example; the three shared climate gallery scripts are removed.
• New climate models: greenhouse_surface_temperature, daily_insolation,
  radiative_convective_temperature, equilibrium_solar_constant,
  red_noise_spectrum, methane_forcing, nitrous_oxide_forcing and
  gregory_regression.
• oceanography history is a dated chronology of 16 breakthroughs, from Newton's
  equilibrium tide (1687) to TEOS-10 (2010), each with its own executed example;
  the three shared oceanography gallery scripts are removed.
• New oceanography models: gerstner_orbit_radius, ekman_spiral_velocity,
  sverdrup_transport, stommel_streamfunction, thermohaline_forcing,
  abyssal_temperature, simplified_seawater_density and the dynamic
  simulate_thermohaline_boxes.