docs: add Re in Burgers entry eq. in docs (#703)

Author: slayoo

examples/docs/pympdata_examples_landing.md

@@ -20,7 +20,7 @@ The examples are grouped by the dimensionality of the computational grid.
 | <mark>advection equation</mark>, homogeneous, several algorithm variants comparison: infinite-gauge, flux-corrected,..                                                                            | `PyMPDATA_examples.Smolarkiewicz_2006_Figs_3_4_10_11_12` |
 | <mark>Size-spectral advection</mark>, particle population condensational growth, coordinate transformation<br>$$ \partial_t (G \psi) + \nabla \cdot (Gu \psi) = 0 $$                              | `PyMPDATA_examples.Olesik_et_al_2022`*                   |
 | <mark>advection equation</mark>, [double-pass donor-cell option](https://osti.gov/biblio/7049237)                                                                                                 | `PyMPDATA_examples.DPDC`                                 |
-| <mark>Burgers' equation</mark><br/>$$ \frac{\partial u}{\partial t} = -\frac{1}{2} \frac{\partial u^2}{\partial x} $$                                                                             | `PyMPDATA_examples.burgers_equation`*<br /><img src="https://github.com/open-atmos/PyMPDATA/releases/download/tip/burgers.gif" width="50%" alt="Burgers eq. example"> |
+| <mark>Burgers' equation</mark><br/>$$ \frac{\partial u}{\partial t} = -\frac{1}{2} \frac{\partial u^2}{\partial x} + \frac{1}{\text{Re}} \frac{\partial^2 u}{\partial x^2} $$                                                                             | `PyMPDATA_examples.burgers_equation`*<br /><img src="https://github.com/open-atmos/PyMPDATA/releases/download/tip/burgers.gif" width="50%" alt="Burgers eq. example"> |
 
 
 ## in 2D