Update README.md

example/test_problem/Hydro/Plummer/README.md

@@ -16,7 +16,8 @@ None
 1. Test the evolution of the Plummer model
    --> `Plummer_Collision` = 0: test the stability of a single Plummer cloud
                              1: test the collision of two Plummer clouds
-2. One can set `NCOMP_PASSIVE_USER=2` and `Plummer_AddColor=1` for `Plummer_Collision==1`
+2. One can set [[NCOMP_PASSIVE_USER=2 | Installation: Simulation-Options#NCOMP_PASSIVE_USER]]
+   and `Plummer_AddColor=1` for `Plummer_Collision==1`
    --> Different clouds will be assigned with different passive scalars
 3. Plummer cloud(s) can have both gas and particles
    --> `Plummer_GasMFrac`: gas mass fraction
@@ -25,5 +26,5 @@ None
    2.  Enable `Plummer_FB_Exp` and/or `Plummer_FB_Acc`
 5. To test mass conservation to the machine precision with mass accretion feedback:
    1. Set `Plummer_FB_ExpMMax = 0.0` (no mass loss in explosion feedback)
-   2. Set `OPT__BC_FLU_* = 1` (periodic BC)
+   2. Set [[OPT__BC_FLU_* | Hydro#OPT__BC_FLU_XM]] = 1 (periodic BC)
    3. Use the gnuplot script `plot_script/plot_mass.gpt`