feat(routes): add Phobos

nav.py

@@ -12,6 +12,7 @@ DISTANCES = {
     ("earth", "gateway"): 0.4,
     ("gateway", "mars"): 225.0,
     ("gateway", "venus"): 41.0,
+    ("mars", "phobos"): 0.01,
 }
 
 # Every route starts at Earth.
@@ -19,6 +20,7 @@ ROUTES = {
     "moon": ["earth", "moon"],
     "mars": ["earth", "gateway", "mars"],
     "venus": ["earth", "gateway", "venus"],
+    "phobos": ["earth", "gateway", "mars", "phobos"],
 }
 
 NAMES = {
@@ -27,6 +29,7 @@ NAMES = {
     "gateway": "Lunar Gateway",
     "mars": "Mars",
     "venus": "Venus",
+    "phobos": "Phobos",
 }
 
 CRUISE_SPEED = 0.87  # million km per day