fix: CSS RGB/HSL variables (Alpha usage)

[alic3dev]

CSS variables are currently being built without commas in their declaration which is preventing them from working with alpha values. Adding in commas between the individual values fixes this issue and allows the variables to be used with rgba and hsla again.

Changes in this PR

• Adds commas between individual RGB/HSL values during CSS build process
• Updates CSS usage documentation to include a comma for rgba/hsla usage

Without commas (Previous)

Works without alpha

Doesn't work with alpha

With commas (Fixed)

Works without alpha

Works with alpha

[uncenter]

Instead of rgba(var(--ctp-latte-blue-rgb) 0.9) can't you do rgba(var(--ctp-latte-blue-rgb) / 0.9)? Without commas I believe you are supposed to use a / to mark the alpha value.

[alic3dev]

@uncenter You are correct! I'll close this PR and open another one with an update to the documentation instead, thanks!