webdoc: regularize OffspecSim

hugo/content/py/sim/offspec/index.md

@@ -3,7 +3,28 @@ title = "Off-specular"
 weight = 20
 +++
 
-### Off-Specular scattering
+## Off-specular scattering simulation
+
+To set up and run a simulation with off-specular scattering, use
+```python
+import bornagain as ba
+scan = ba.AlphaScan(...)
+sample = ...
+detector = ba.OffspecDetector(...)
+simulation = ba.OffspecSimulation(scan, sample, detector)
+# ... set options
+result = simulation.simulate()
+```
+
+For the constructor arguments, see sections [scan]({{% ref-py "instr/scan" %}}),
+[sample]({{% ref-py "sample" %}}), and [OffspecDetector]({{% ref-py "instr/det/offspec" %}}).
+
+For optional settings, see [simulation options]({{% ref-py "sim/options" %}}).
+
+For the return type of function `simulate()`,
+see [SimulationResult]({{% ref-py "result/simulation-result" %}}).
+
+#### Example
 
 Off-specular scattering from a monodisperse distribution of long boxes.
 

hugo/content/py/sim/reflectometry/_index.md

@@ -24,7 +24,7 @@ For the return type of function `simulate()`,
 see [SimulationResult]({{% ref-py "result/simulation-result" %}}).
 
 
-### Example script
+### Example
 
 As introductory example, we simulate specular reflectometry
 by a sample that consists of 10 Ti/Ni double layers on a Si substrate.