feat(colorPicker): Add color picker to docs

What does this MR do?

A shared color picker component was created in gitlab-org/gitlab!48606 (merged). This change captures the functionality within the Pajamas documentation. Its a follow up to #773.

Does this MR meet the acceptance criteria?

• The MR title and commit message meet the Pajamas commit conventions
• Add a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Include MR scope that reflects the purpose of the change in the description
  • For example, if this MR is focused on usage guidelines, addressing accessibility challenges could be added separately with a different MR
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