[docslides][ffpm] Fix typos

slides/coupled_ff-pm.md

 ---
-title: Coupled Free-Flow and Porous Media Flow Models in DuMu<sup>X</sup>
+title: Coupled Free-Flow and Porous Media Flow Models in DuMu^x^
 ---
 
 # Motivation
@@ -15,7 +15,7 @@ Fig.1 - Evaporation of soil water (Heck et al. (2020))<sup>1</sup>
 
 * Evaporation of soil water
 * Soil salinization
-* Underground storage (e.g. CO2, atmoic waste)
+* Underground storage (e.g. CO2, atomic waste)
 
 ## Technical Issues
 
@@ -71,7 +71,7 @@ Fig.5 - Exchange processes at the free-flow porous-medium interface at different
 * Stokes / Navier-Stokes / RANS
 * 1-phase, n-components, non-equilibrium
 
-**Interface condtions:**
+**Interface conditions:**
 
 * no thickness, no storage
 * local thermodynamic equilibrium
@@ -80,7 +80,7 @@ Fig.5 - Exchange processes at the free-flow porous-medium interface at different
 
 **Porous media:**
 
-* Darcy/ Forchheimer / Richards
+* Darcy / Forchheimer / Richards
 * m-phases, n-components, non-isothermal
 
 </font>