Add examples: - $L^1$-minimization [two-body problem](https://caillau.perso.math.cnrs.fr/research/sicon-2016.pdf). - $L^1$-minimization [CR3BP](https://caillau.perso.math.cnrs.fr/research/cele-2012.pdf). - [Minimum time, CR3BP](https://caillau.perso.math.cnrs.fr/research/sicon-2012.pdf).
