updated docs

docs/src/examples/delta_competition_example.md

@@ -34,6 +34,7 @@ Here is how you can visualise the landscape.
 using GraphPlot
 gplot(g, collect(1:nodes), collect(1:nodes))
 ```
+![delta_comp_pos](../assets/tutorials/line.png)
 
 ## Defining competition processes
 We propose that any individual have a constant birth rate, and competes with all the individuals present in the same patch. Let ``i \in \N``,``x_i \in \{1,2,\dots,9\}``.

docs/src/examples/gradient.md

@@ -2,6 +2,12 @@
 
 In this tutorial, we model agents evolving on a discrete segment, where each patch favours an optimal adaptive trait, along a gradient. This is typically the case along an altitudinal gradient.
 
+Here is what the geographical space looks like.
+
+![delta_comp_pos](../assets/tutorials/adapt_line.png)
+
+Every colour stands for a different optimal trait.
+
 ## Run the world
 ```julia
 using Revise,ABMEv,Plots,UnPack