docs(aio): remove example specific .gitignore files

All the files that should be ignored are defined in the
`aio/content/examples/.gitigore` folder.

aio/content/examples/cli-quickstart/.gitignore

@@ -1,45 +0,0 @@
-# See http://help.github.com/ignore-files/ for more about ignoring files.
-
-# compiled output
-/dist
-/tmp
-
-# dependencies
-/node_modules
-
-# IDEs and editors
-/.idea
-.project
-.classpath
-.c9/
-*.launch
-.settings/
-*.sublime-workspace
-
-# IDE - VSCode
-.vscode/*
-!.vscode/settings.json
-!.vscode/tasks.json
-!.vscode/launch.json
-!.vscode/extensions.json
-
-# misc
-/.sass-cache
-/connect.lock
-/coverage/*
-/libpeerconnection.log
-npm-debug.log
-testem.log
-/typings
-
-# e2e
-/e2e/*.js
-/e2e/*.map
-
-#System Files
-.DS_Store
-Thumbs.db
-
-!src/styles.css
-!karma.conf.js
-!protractor.conf.js