The script will check some php.ini settings warn you if they
are set incorrectly, and then download the latest composer.phar
in the current directory. These lines will, in order:

- Download the installer SHA-384 to the current directory
- Download the installer to the current directory
- Verify the installer SHA-384 which you can also cross-check https://composer.github.io/pubkeys.html
- Run the installer
- Remove the installer & the installer SHA-384

Signed-off-by: Rémy Coutable <remy@rymai.me>

This documents the `GIT_SUBMODULE_STRATEGY` feature added in
gitlab-ci-multi-runner version 1.10.

[ci skip]

Fixed typo in test-and-deploy-ruby-application-to-heroku.md

See merge request !8236

The button allows to choose a ".gitlab-ci.yml" template that automatically
sets up the deployment of an application.
The currently supported template is Kubernetes template.

Rename "Online terminal" to "Web terminal" in the documentation

## What does this MR do?

Renames online terminals to web terminals in some recently merged documentation

## Are there points in the code the reviewer needs to double check?

I think I've caught all the links

## Why was this MR needed?

We're calling it 'web terminal' in the release post, and consistency is :sparkles: 

https://gitlab.com/gitlab-com/www-gitlab-com/merge_requests/4007/diffs#note_20283597

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !8190

Add doc for pipeline duration

The description was copied and modified from !6084

See merge request !6445