readme final update

README.md

@@ -75,12 +75,7 @@ To create a .geo file compatible with the program, some rules must be respected:
   1. All the lines belonging to the interface between the FEM domain and the different BEM domains must be specified as a single `Physical Curve("BEM_FEM_boundary, x)={List_of_the_interface_lines}`. As an example, if `Line(1)`, `Line(4)` and `Line(5)` belong to the intersection of the BEM domains and the FEM domain: 
         <pre><code> Physical Curve("BEM_FEM_boundary", x) = {1, 4, 5};<code><pre>
 - For the mechanical or the coupled solver, the user can choose between the linear or non-linear iterative solver, by setting 
-  <pre><code> SetNumber("Non_linear_solver",0);<code><pre> 
-  
-  for the linear solver, or
-  <pre><code> SetNumber("Non_linear_solver",1);<code><pre> 
-  
-  for the non-linear solver.
+  `SetNumber("Non_linear_solver",0);` for the linear solver, or `SetNumber("Non_linear_solver",1);` for the non-linear solver.