Add SAML tutorials

What does this MR do?

Adds a few SAML tutorials for Gitlab.com. These tutorials are based on the existing documentation, but still need validation from people with access to an Okta org/Entra tenant.

There are three tutorials attached to this MR:

• saml_okta.md: Explains how to set up SAML for an Okta org
• saml_entra.md: Explains how to set up SAML for an Entra tenant
• saml_saas.md: Combines the two other tutorials.

Outside of references to the specific IdP, the tutorials are largely the same. The only real differences are in steps 2 & 3. The combined approach lets us reduce the number of tutorials we need. We could theoretically add more steps for any other IdPs as new tabs.

We need to decide if we want to have a seperate tutorial for each IdP, or a single tutorial with multiple tabs. Depending on the approach, we will need to remove at least one of these files before merging.

Note to reviewers

The content in steps 1 & 4-8 is almost identical between all topics. There are very slight differences based on the name of the IdP.

Preview build

Link

Related issues

Docs: Investigate tutorial creation for SAML, S... (#577195)

Author's checklist

• Optional. Consider taking the GitLab Technical Writing Fundamentals course.
• Follow the:
  • Documentation process.
  • Documentation guidelines.
  • Style Guide.
• If you're adding a new page, add the product availability details under the H1 topic title.
• If you are a GitLab team member, request a review based on:
  • The documentation page's metadata.
  • The associated Technical Writer.

If you are a GitLab team member and only adding documentation, do not add any of the following labels:

• ~"frontend"
• ~"backend"
• ~"type::bug"
• ~"database"

These labels cause the MR to be added to code verification QA issues.

Reviewer's checklist

Documentation-related MRs should be reviewed by a Technical Writer for a non-blocking review, based on Documentation Guidelines and the Style Guide.

If you aren't sure which tech writer to ask, use roulette or ask in the #docs Slack channel.

• If the content requires it, ensure the information is reviewed by a subject matter expert.
• Technical writer review items:
  • Ensure docs metadata is present and up-to-date.
  • Ensure the appropriate labels are added to this MR.
  • Ensure a release milestone is set.
  • If relevant to this MR, ensure content topic type principles are in use, including:
    • The headings should be something you'd do a Google search for. Instead of Default behavior, say something like Default behavior when you close an issue.
    • The headings (other than the page title) should be active. Instead of Configuring GDK, say something like Configure GDK.
    • Any task steps should be written as a numbered list.
    • If the content still needs to be edited for topic types, you can create a follow-up issue with the docs-technical-debt label.
• Review by assigned maintainer, who can always request/require the reviews above. Maintainer's review can occur before or after a technical writer review.