Orientations example

Adds an example how to deal with orientations.

docs/src/examples/orientations.md

@@ -7,6 +7,7 @@ The data used in this example is provided by [KM3NeTTestData.jl](https://git.km3
 
 ```@example 1
 using KM3io
+using KM3NeTTestData
 using CairoMakie
 using Dates
 ```
@@ -18,6 +19,13 @@ ax_yaw =  Axis(fig[1, 1])
 ax_pitch_and_roll =  Axis(fig[1, 2])
 ```
 
+We load the orientations data and extract the quaternions including the corresponding times from it:
+
+```@example 1
+o = read(datapath("calib", "KM3NeT_00000049_0.0.0_00007631_00007676_1.orientations.root"), Orientations)
+qdata = o(808972593)
+```
+
 The times are converted to `DateTime` objects, which Makie will understand and
 display them in a human readable way.