Update docu

Author: ufechner7

docs/src/winchcontroller.md

@@ -68,6 +68,7 @@ calc_v_set(wc::WinchController, v_act, force, f_low; v_set_pc=nothing)
 get_set_force(wc::WinchController)
 get_state(wc::WinchController)
 get_status(wc::WinchController)
+get_v_err(wc::WinchController)
 on_timer(wc::WinchController)
 ```
 

src/wc_components.jl

@@ -453,7 +453,6 @@ Compute and return the velocity error for the given `SpeedController` instance `
 # Returns
 - The velocity error `v_err` [m/s]. 
   If the controller is inactive, it returns `NaN`.
-
 """
 function get_v_err(sc::SpeedController)
     if sc.inactive

src/winchcontroller.jl

@@ -216,6 +216,18 @@ function get_status(wc::WinchController)
     result
 end
 
+"""
+    get_v_err(wc::WinchController)
+
+Compute and return the velocity error for the given `WinchController` instance `sc`.
+
+# Arguments
+- wc::[WinchController](@ref): The winch controller object for which the velocity error is to be calculated.
+
+# Returns
+- The velocity error `v_err` [m/s]. 
+  If the speed controller is inactive, it returns `NaN`.
+"""
 function get_v_err(wc::WinchController)
     get_v_err(wc.sc)
 end