feat(line-chart): Add no data guidelines

What does this MR do?

In GitLab a pattern has emerged to represent breaks in line chart data with a dashed line. This MR adds the guideline to Pajamas.

Issues that have landed on this solution:

• Present Lead time for MRs to be deployed to pro... (gitlab-org/gitlab#250329 - closed)
• Improve rendering in DORA4 Lead time chart (gitlab-org/gitlab#329645 - closed)
• Aggregate project release metrics in the CI/CD ... (gitlab-org/gitlab#259703 - closed)
• Present Lead time for MRs to be deployed to pro... (gitlab-org/gitlab#325061 - closed)

See it live:

• https://gitlab.com/gitlab-com/www-gitlab-com/-/pipelines/charts?chart=lead-time

Related to gitlab-org/gitlab!96634 (comment 1085329286)

Does this MR meet the acceptance criteria?

• The MR title and commit messages meet the Pajamas commit conventions.
• The “What does this MR do?” section in the MR description is filled out, explaining the reasons for and scope of the proposed changes, per “Say why not just what”.
  • For example, if the MR is focused on usage guidelines, addressing accessibility challenges could be added in a separate MR.
• Relevant label(s) are applied to the MR.
• The MR is added to a milestone.
• [-] If creating a new component page from scratch, it follows the page template structure.
• Content follows the Pajamas voice and tone guidelines, falling back on the GitLab Documentation Style Guide when needed.
• Related pages are cross-linked, where helpful. Component pages have related components and patterns defined in their Markdown front matter.
• If embedding a Figma file, it follows the Figma embed guide.
• Review requested from any GitLab designer or directly from a maintainer or trainee maintainer.

Links