[Dev] 1.5 branding for downstream RHELAI

[Misjohns]

RHELAI Branding

For RHELAI 1.5, we need to replace the iLab branding and UI tokens with the Red Hat RHEL branding and UI tokens.

• Use PF default design tokens
• Use Red Hat Enterprise Linux logo in masthead
• Replace any InstructLab language with Red Hat Enterprise Linux

@Misjohns Will work with dev to provide the necessary resources and guidance.
@jeff-phillips-18 FYI

[Misjohns]

Delivered logos for both iLab and RHELAI for masthead, light and dark themes.