Previously, the `.gitignore` file that is part of the boilerplate files
for CLI-based docs examples (located in
`aio/tools/examples/shared/boilerplate/cli/`) was not added to the
example projects, because it was not included in the boilerplate file
list in `example-boilerplate.js`.
This commit fixes it by adding the `.gitignore` file to the list. This
ensures that docs examples more closely match CLI-generated projects.
PR Close#38173