[slides][materialsystem] Add file paths for code blocks.

slides/materialsystem.md

@@ -50,8 +50,6 @@ More resources can be found [in the code documentation](https://dumux.org/docs/d
 
 ## Example interfaces
 
-* See _dumux/dumux/material/components/air.hh_
-
 ```cpp
 static Scalar gasDensity(Scalar temperature, Scalar pressure)
 {
@@ -59,24 +57,19 @@ static Scalar gasDensity(Scalar temperature, Scalar pressure)
     return IdealGas::density(molarMass(), temperature, pressure);
 }
 ```
+<span style="font-size: 0.4em; position: relative; top: -38px; color: gray;">File: `dumux/dumux/material/components/air.hh`</span>
 
 ## Example interfaces
 
 ```cpp
-static Scalar gasHeatCapacity(Scalar temperature, Scalar pressure)
-{
-    constexpr Scalar cpVapA = 19.25;
-    constexpr Scalar cpVapB = 0.05213;
-    constexpr Scalar cpVapC = 1.197e-5;
-    constexpr Scalar cpVapD = -1.132e-8;
-
-    return 1/molarMass()*(
-        cpVapA + temperature*(
-            cpVapB/2 + temperature*(cpVapC/3 + temperature*(cpVapD/4))
-        )
-    );
-}
+static Scalar gasHeatCapacity(Scalar T, Scalar pressure)
+    {
+        const auto cp = shomateMethod.heatCapacity(T); // J/(mol K)
+        return cp / molarMass(); // J/(kg K)
+    }
+
 ```
+<span style="font-size: 0.4em; position: relative; top: -38px; color: gray;">File: `dumux/dumux/material/components/ch4.hh`</span>
 
 # Fluid systems
 
@@ -111,6 +104,7 @@ static Scalar heatCapacity(const FluidState& fluidState, int phaseIdx)
     ...
 }
 ```
+<span style="font-size: 0.4em; position: relative; top: -38px; color: gray;">File: `dumux/dumux/material/fluidsystems/brine.hh`</span>
 
 # Binary coefficients
 
@@ -141,7 +135,7 @@ static Scalar gasDiffCoeff(Scalar temperature, Scalar pressure)
     return Daw*(pg0/pressure)*pow((temperature/T0), theta);
 }
 ```
-
+<span style="font-size: 0.4em; position: relative; top: -38px; color: gray;">File: `dumux/dumux/material/binarycoefficients/h2o_air.hh`</span>
 
 # Solid systems
 
@@ -269,7 +263,7 @@ _CompositionFromFugacities_ : takes all component fugacities, the temperature an
 
 ```cpp
 template<class TypeTag>
-struct FluidSystem<TypeTag, TTag::H2OAir>
+struct FluidSystem<TypeTag, TTag::DrainageProblem>
 {
 private:
     using Scalar = GetPropType<TypeTag, Properties::Scalar>;
@@ -283,6 +277,7 @@ public:
     >;
 };
 ```
+<span style="font-size: 0.4em; position: relative; top: -38px; color: gray;">File: `dumux/test/porenetwork/2pnc/properties.hh`</span>
 
 
 # Example: From components to solid system
@@ -307,7 +302,7 @@ struct SolidSystem<TypeTag, TTag::ThermoChem>
     >;
 };
 ```
-
+<span style="font-size: 0.4em; position: relative; top: -38px; color: gray;">File: `dumux/test/porousmediumflow/1pncmin/nonisothermal/properties.hh`</span>
 
 # Exercise