Update pipelines.md

What does this MR do?

attempt to solve: https://gitlab.com/gitlab-org/gitlab-ce/commit/a03cadcdbf3024ec59234a07a9b87884de5cc7dc#note_14172234

the word isn't visible anyway, don't know what original author intended to say. at least it fixes the stages link now.

Does this MR meet the acceptance criteria?

• Documentation created/updated