Update refraction scaling docs

docs/source/reference/modding/settings/water.rst

@@ -98,10 +98,10 @@ refraction scale
 
 Simulates light rays refracting when transitioning from air to water, which causes the space under water look scaled down
 in height when viewed from above the water surface. Though adding realism, the setting can cause distortion which can
-make for example aiming at enemies in water more challenging, so it is off by default (i.e. set to 1.0).
+make for example aiming at enemies in water more challenging, so it is off by default (i.e. set to 1.0). To get a realistic
+look of real-life water, set the value to 0.75.
 
 This setting only applies if water shader is on and refractions are enabled. Note that if refractions are enabled and this
 setting if off, there will still be small refractions caused by the water waves, which however do not cause such significant
 distortion.
 
-TODO: setting via GUI? Interation with rttsize?