[Docs] Broken Images & Inconsistencies in the Multi-Brand design system sample

[brionmario]

Is your suggestion related to a missing or misleading document? Please describe.

There are several documentation issues in the current docs release.

1. There are broken images in the Storybook

2. The dark mode of the Multi-Brand design system sample has a invalid teal color as the primary.

Describe the improvement

The images shouldn't be broken and the dark mode should have the default WSO2 orange color as the primary.