Add projection description for Lambert Azimuthal Equal-Area
Lambert Azimuthal Equal Area
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+This projection was developed by Johann Heinrich Lambert in 1772 and is typically used
+for mapping large regions like continents and hemispheres. It is an azimuthal,
+equal-area projection, but is not perspective. Distortion is zero at the center of the
+projection, and increases radially away from this point.
+
``Alon0/lat0[/horizon]/width``: ``lon0`` and ``lat0`` specifies the projection center.
``horizon`` specifies the max distance from projection center (in degrees, <= 180,
default 90).
