There's a standard Visual Studio .gitignore file available here.
It includes this section:
# Build results
[Dd]ebug/
[Dd]ebugPublic/
[Rr]elease/
[Rr]eleases/
x64/
x86/
bld/
[Bb]in/
[Oo]bj/
[Ll]og/
Why don't those lines start with the gitignore pattern format **/ so that the search includes all subdirectories?
Relative paths (as your directory names) already are ignored everywhere.
If you create a structure
foo/
bar/x.txt
bar/x.txt
(where x.txt is just fluff to have non-empty directories)
and have a .gitignore file containing just
bar
then git is ignoring both bar directories.
Absolute paths like /bar would only ignore a top-level directory instead.
Are you sure that you're seeing a different behavior?
The documentation you linked to contains this:
Two consecutive asterisks ("**") in patterns matched against full pathname may have special meaning:
A leading "**" followed by a slash means match in all directories. For example, "**/foo" matches file or directory "foo" anywhere, the same as pattern "foo". "**/foo/bar" matches file or directory "bar" anywhere that is directly under directory "foo".
(emphasis mine)