ocaml-globe: enable MDX on lib/satellite.mli, replace pseudocode example
The Quick Start was a stack of three pseudocode call-shapes with
free [pos]/[vel]/[color]/[epoch_unix]/[tle]/[state]/[points]
variables. Replaced with a single Kepler-propagation example that
builds a real Satellite.t from a ~6800 km circular-orbit state
vector and asserts on epoch round-trip and the color tuple.