fix: add docs + test for initial no-scan work

[terriko]

I'm going to get this merged as-is, but I'll set up an issue reminding us that we want a test and a preliminary docs entry (likely explaining what works and what doesn't, such as the fact that it won't operate without cve data yet)

Originally posted by @terriko in #5122 (review)

Making this as a reminder for @joydeep049
We'd like

• a really basic test (i.e. something that shows that the --no-scan flag can be used from the CLI but doens't care much what it does)
• some initial information for the docs, likely explaining what works now and maybe a section about what's planned.

[joydeep049]

Should we wait and add a bit more features before updating the docs? I was hoping to get the language parser work done before changing the documentation, as discussed in the last meet.
Or I could also add some docs now as well. Totally fine with me

[terriko]

I think we want really short "this option exists but it doesn't fully work yet" probably both in the help text and in the manual or readme. Mostly I don't want people who haven't been following development to get too excited when they see it in the pre-release.