Added a pre-commit config file and reformatted all the files accordingly by using it.

docs/source/comparisons_numerical.rst

@@ -50,4 +50,3 @@ Results
     Input impedance (resistive and reactive) of a bowtie antenna in free space using FDTD (gprMax) and MoM (MATLAB) models.
 
 The results from the FDTD and MoM modelling techniques are in very good agreement. The biggest mismatch occurs in the resistive part of the input impedance at frequencies above 3GHz.
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