changed paper footnotes to hyperlinks

joss/paper.md

@@ -40,15 +40,9 @@ Modeling the motion of small solar system bodies is of utmost importance when lo
 
 In this paper, we present ``GRSS``, the Gauss-Radau Small-body Simulator, an open-source library for orbit determination and propagation of small bodies in the solar system. ``GRSS`` is an open-source software library with a C++11 foundation and a Python binding. The propagator is based on the ``IAS15`` algorithm, a 15<sup>th</sup> order integrator based on Gauss-Radau quadrature [@Rein2014]. Only the particles of interest are integrated within ``GRSS`` to reduce computational cost. The states for the planets and 16 largest main-belt asteroids are computed using memory-mapped JPL digital ephemeris kernels [@Park2021] as done in the ``ASSIST`` orbit propagator library [@Holman2023]. In addition to the propagator, the C++ portion of the library also has the ability to predict impacts and calculate close encounter circumstances using various formulations of the B-plane [@Kizner1961; @Opik1976; @Chodas1999; @Milani1999; @Farnocchia2019].
 
-The C++ functionality is exposed to Python through a binding generated using ``pybind11``[^1]. The Python layer of ``GRSS`` uses the propagator as the foundation to compute the orbits of small bodies from a given set of optical and/or radar astrometry from the Minor Planet Center[^2], the JPL Small Body Radar Astrometry database[^3], and the Gaia Focused Product Release solar system observations database[^4]. Additionally, the orbit determination modules also have the ability to fit especially demanding measurements such as stellar occultations. These capabilities of the ``GRSS`` library have already been used to study the the heliocentric changes in the orbit of the (65803) Didymos binary asteroid system as a result of the DART impact [@Makadia2022; @Makadia2024] and for analyzing the impact locations of two asteroids, 2024 BX<sub>1</sub> and 2024 RW<sub>1</sub> [@Makadia2024b].
+The C++ functionality is exposed to Python through a binding generated using [``pybind11``](https://github.com/pybind/pybind11). The Python layer of ``GRSS`` uses the propagator as the foundation to compute the orbits of small bodies from a given set of optical and/or radar astrometry from the [Minor Planet Center](https://minorplanetcenter.net), the [JPL Small Body Radar Astrometry database](https://ssd.jpl.nasa.gov/sb/radar.html), and the [Gaia Focused Product Release solar system observations database](https://www.cosmos.esa.int/web/gaia/fpr#SSOs). Additionally, the orbit determination modules also have the ability to fit especially demanding measurements such as stellar occultations. These capabilities of the ``GRSS`` library have already been used to study the the heliocentric changes in the orbit of the (65803) Didymos binary asteroid system as a result of the DART impact [@Makadia2022; @Makadia2024] and for analyzing the impact locations of two asteroids, 2024 BX<sub>1</sub> and 2024 RW<sub>1</sub> [@Makadia2024b].
 
-``GRSS`` will continue to be developed in the future, with anticipated contributions including the ability to perform mission studies for future asteroid deflections. ``GRSS`` is publicly available to the community through the Python Package Index and the source code is available on GitHub[^5]. Therefore, ``GRSS`` is a reliable and efficient tool that the community has access to for studying the dynamics of small bodies in the solar system.
-
-[^1]: <https://github.com/pybind/pybind11>
-[^2]: <https://minorplanetcenter.net/>
-[^3]: <https://ssd.jpl.nasa.gov/sb/radar.html>
-[^4]: <https://www.cosmos.esa.int/web/gaia/fpr#SSOs>
-[^5]: <https://github.com/rahil-makadia/grss>
+``GRSS`` will continue to be developed in the future, with anticipated contributions including the ability to perform mission studies for future asteroid deflections. ``GRSS`` is publicly available to the community through the Python Package Index and the [source code](https://github.com/rahil-makadia/grss) is available on GitHub. Therefore, ``GRSS`` is a reliable and efficient tool that the community has access to for studying the dynamics of small bodies in the solar system.
 
 # Acknowledgements