Added $ symbol to indicate terminal.

Author: rsanfer

_tutorials/multiphysics/Basic_RHT.md

@@ -151,7 +151,7 @@ Follow the links provided to download the [config](https://github.com/su2code/Tu
 Execute the code with the standard command
 
 ```
-SU2_CFD config_radiation.cfg
+$ SU2_CFD config_radiation.cfg
 ```
 
 which will show the following convergence history:

_tutorials/multiphysics/Static_FSI.md

@@ -248,7 +248,7 @@ Also, you will need two files for the [channel mesh](https://github.com/su2code/
 Execute the code with the standard command and using the multi-zone config file
 
 ```
-SU2_CFD config_fsi_steady.cfg
+$ SU2_CFD config_fsi_steady.cfg
 ```
 
 which will show the following convergence history:

_tutorials/structural_mechanics/Multiple_Material.md

@@ -86,7 +86,7 @@ Finally, given the flexibility of the regions R1 and R3, an incremental approach
 Follow the links provided to download the [config](https://github.com/su2code/Tutorials/blob/master/structural_mechanics/cantilever/config_nonlinear_multimaterial.cfg), [mesh](https://github.com/su2code/Tutorials/blob/master/structural_mechanics/cantilever/mesh_cantilever.su2) and [element_properties](https://github.com/su2code/Tutorials/blob/master/structural_mechanics/cantilever/element_properties.dat) files. Execute the code with the standard command
 
 ```
-SU2_CFD config_nonlinear_multimaterial.cfg
+$ SU2_CFD config_nonlinear_multimaterial.cfg
 ```
 
 which will show the following convergence history:

_tutorials/structural_mechanics/Nonlinear_Elasticity.md

@@ -94,7 +94,7 @@ MARKER_PRESSURE = ( left, 1E3, upper, 0, right, 0)
 Follow the links provided to download the [config](https://github.com/rsanfer/Tutorials/blob/master/structural_mechanics/cantilever/config_nonlinear.cfg) and [mesh](https://github.com/rsanfer/Tutorials/blob/master/structural_mechanics/cantilever/mesh_cantilever.su2) files. Execute the code with the standard command
 
 ```
-SU2_CFD config_nonlinear.cfg
+$ SU2_CFD config_nonlinear.cfg
 ```
 
 which will show the following convergence history: