Merge branch 'fix/intro-discretization-figures' into 'master'

[slides][intro] Use updated discretization images from Dumux documentation.

See merge request !291

slides/intro.md

@@ -366,6 +366,18 @@ method with piecewise linear polynomial functions ($\mathrm{P}_1/\mathrm{Q}_1$)
 
 <img src="img/box.png" width="70%"/>
 
+## Diamond Scheme 
+
+Face-centered finite-volume scheme based on non-conforming finite-element spaces
+
+<img src="img/fcdiamond.png" width="70%"/>
+
+## PQ1 Bubble Scheme
+
+Control-volume finite element scheme based on $\mathrm{P}_1/\mathrm{Q}_1$ basis functions with enrichment by a bubble function
+
+<img src="img/pq1bubble.png" width="70%"/>
+
 ## Finite Volume Method on Staggered Control Volumes
 
 * Uses a finite volume method with different staggered control volumes for different equations
@@ -375,7 +387,7 @@ method with piecewise linear polynomial functions ($\mathrm{P}_1/\mathrm{Q}_1$)
 
 ## Staggered Grid Discretization
 
-<img src="img/staggered_grid.png"/>
+<img src="img/fcstaggered.png"/>
 
 # Model Components