Update description of view_controller_chains

[christophfroehlich]

Update the docs with the current output and adds a hint where the PDF is saved.

[codecov-commenter]

Codecov Report

Merging #1094 (be4237a) into master (925f5f3) will decrease coverage by 2.21%.
Report is 504 commits behind head on master.
The diff coverage is 34.83%.

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@@            Coverage Diff             @@
##           master    #1094      +/-   ##
==========================================
- Coverage   34.61%   32.41%   -2.21%     
==========================================
  Files          52       94      +42     
  Lines        2981     9937    +6956     
  Branches     1855     6694    +4839     
==========================================
+ Hits         1032     3221    +2189     
- Misses        310      789     +479     
- Partials     1639     5927    +4288     

Flag	Coverage Δ
unittests	32.41% <34.83%> (-2.21%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
controller_manager/src/controller_manager.cpp	37.94% <ø> (-1.77%)	⬇️
controller_manager/src/ros2_control_node.cpp	0.00% <0.00%> (ø)
..._interface/include/hardware_interface/actuator.hpp	100.00% <ø> (ø)
...ce/include/hardware_interface/async_components.hpp	0.00% <0.00%> (ø)
...re_interface/include/hardware_interface/sensor.hpp	100.00% <ø> (ø)
...re_interface/include/hardware_interface/system.hpp	100.00% <ø> (ø)
hardware_interface/src/resource_manager.cpp	46.76% <ø> (-6.87%)	⬇️
hardware_interface/src/sensor.cpp	50.52% <ø> (ø)
hardware_interface/src/system.cpp	55.45% <ø> (ø)
...rface/test/mock_components/test_generic_system.cpp	9.42% <ø> (ø)
... and 70 more

... and 20 files with indirect coverage changes