Move 1Password info from docs.gitlab.com to the Handbook

Per our Contributor and Developer docs page:

This content is intended for members of the GitLab Team as well as community contributors. Content specific to the GitLab Team should instead be included in the Handbook.

We have several references to the internal GitLab 1Password vault at docs.gitlab.com, which should be moved IMO to the 1Password guide of the Handbook:

• https://docs.gitlab.com/ee/development/pipelines#pre-clone-step
• https://docs.gitlab.com/ee/development/documentation/site_architecture/#algolia-search-engine

Some places in our docs.gitlab.com documentation have a correct link to the handbook:

(If you’re a GitLab Team Member, find credentials in the [GitLab shared 1Password account](https://about.gitlab.com/handbook/security/#1password-for-teams))