The pipelines docs are under `user/project` but should be
with the rest of the CI docs under `/ci`

This change updates the location of `settings.md` and the
`pipelines.md`

* move `/user/project/settings.md` to `ci/pipelines` folder

* update references to `settings.md` to point to the new location

* move images to the new location and delete the old directory

* move `pipelines.md` to `index.md` in the new ci/pipelines folder