UI: explore lighter background syntax highlighting

[dwdougherty]

DOC-4311

Hi folks. I tried to use Augment in VS Code to modify code blocks to use a lighter overall theme (one of @kaitlynmichael's requests from a long way back). This PR is the result. Please take a look and let me know what you think and also if there are any bugs. Here are some reference pages:

https://redis.io/docs/staging/DOC-4311/develop/
https://redis.io/docs/staging/DOC-4311/develop/data-types/strings/
https://redis.io/docs/staging/DOC-4311/commands/set/

[andy-stark-redis]

@dwdougherty Although I don't mind the current black backgrounds, I get that the lighter backgrounds might make the contents easier to read and reduce eye strain if you are reading a lot of them, so this is probably a good move. However...

• The pale background directly against the white page doesn't seem enough to differentiate the example box. I'd say adding a black border line, even a thin one, would look better. Or maybe a drop shadow is another option?
• The tab selectors on the TCE boxes look pretty odd now. The original black hides the fact that the buttons are different heights when selected vs not selected. Also, having a visible box around the selected tab button looks OK, but having different boxes around the unselected buttons is visually distracting.
• Redis logo looks nice and adds colour, but perhaps have it slightly smaller?

The look of the CLI-only boxes is quite nice (although still needs the border/shadow) and the little Redis logo looks good there. Maybe adapt the TCE boxes to use the same styling as the CLI boxes (perhaps even keep the Redis logo)? If you make the background of the unselected tab buttons the same as the window bar and only distinguish the selected button, it would create a similar effect to our existing tabs, but keep the advantages of the light background.

Another option might be to use styling that looks a bit like Github tab boxes (like the one I am typing this comment into right now)? The backgrounds for these are white, but there's enough to distinguish them from the main page background, and they also make the tab metaphor more explicit.

[dwdougherty]

Thanks for your feedback, @andy-stark-redis! Much appreciated. I'll see what I can do to address your issues.

[kaitlynmichael]

I'm just now realizing that this might cause eye strain for users on dark mode. Maybe we should leave them dark?

[dwdougherty]

Well... poodoo. That said, maybe trying implement dark mode is a better use of my time. I'll close this PR.