Updating instructions for converting images
Renaming PNG file.

The documentation no longer uses example2.cpp, but instead
consistently uses example1.cpp
Removing this old file.
Baseline updates plug test file changes.

Example1 was changed to use the shorted source file in
example2.  The example5.sh script was changed to use the example1
source file.
Baseline updates

Due to copying example1.cpp to example2.cpp
Documentation update
Documentation changes for gcovr 3.2
Merge branch 'master' of https://github.com/gcovr/gcovr