Add section Contributing.

Author: ufechner7

docs/src/tips_and_tricks.md

@@ -1,6 +1,6 @@
-## Tips and tricks
+# Tips and tricks
 
-### What can this model simulate
+## What can this model simulate
 The following bodies can be simulated:
 
 - conventional bodies, consisting of one or more wings
@@ -10,18 +10,21 @@ The following bodies can be simulated:
 To build the geometry of a RAM-air kite, a 3D .obj file can be used as input. In addition a `.dat` file is needed.
 It should have two columns, one for the `x` and one for the `y` coordinate of the 2D polar that is used.
 
-### RAM-air kite model
+## RAM-air kite model
 If running the example `ram_air_kite.jl` fails, try to run the `cleanup.jl` script and then try again. Background: this example caches the calculated polars. Reading cached polars can fail after an update.
 
-### Output formats
+## Output formats
 Currently, the `solve!()` function returns the results as [VSMSolution](@ref) struct. The function solve() returns a dictionary with the results. The `solve!()` function is faster, and the `solve()` contains many more entries, therefore the first function is good for integration in dynamic models and the second one better suited for aerodynamic analysis.
 
-### Performance
+## Performance
 Calling `init!(body_aero; init_aero=false)` is very fast. After calling `deform!(wing)`, you have to run `init!(body_aero; init_aero=false)` to apply the deformed wing to the body aerodynamics. This is in turn necessary for the linearization from deformation to aerodynamic coefficients for RAM-air kites.
 
-### Building the documentation locally
+## Contributing
+Please, read [CONTRIBUTING.md](https://github.com/Albatross-Kite-Transport/VortexStepMethod.jl/blob/main/CONTRIBUTING.md)
+
+## Building the documentation locally
 You can build the documentation locally after checking out the source code with git, launching Julia and executing:
-```
+```julia
 include("scripts/build_docu.jl")
 ```
 A browser window should pop up automatically.