Split and merge `syntaxes.json` into `functions.json` and `types.json` about data

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[lahmatiy]

I missed when functions.json was added. As to me it should be merged back into syntaxes.json. The types.json is actually contains generic types, in other words types that has no syntax definition but a prose definition in CSS specs. Having a split in functions and other types makes no sense in terms of CSS.

[yarusome]

I found that types.json contain both prose-only types (such as <number>) and types that do have syntaxes (such as <display-internal>), meanwhile the schema for types.json doesn't allow for a syntax key. I could add a special case to split types into syntaxes.json and types.json based on the presence/absence of syntax, but this dichotomy seems unnecessary 🤔 (I'll leave units.json as it is despite of the fact that their types are "value" in Webref).

So there're two ways to move forward:

1. Split any data in Webref of the "type" type into syntaxes.json and types.json based on the presence/absence of syntax.
2. Change the schema for types.json, and split syntaxes.json into funtions.json and types.json.

[caugner]

Thank you for opening this issue, and sorry for the long waiting time. 🙏

Unfortunately, I'm not very familiar with mdn/data, so I must be missing some important context here.

@yarusome As I understand, the combined syntaxes.json makes it more difficult for you to diff mdn/data and w3c/webref. Can you explain the background of this diff?

The documented plan has been to deprecate this package in favor of w3c/webref, which is blocked by references to mdn-data in yari. Since this package is used a lot with 26 million weekly downloads, we need to have a very good reason for this breaking change.

If all the data in mdn-data can be derived from w3c/webref (can it?), then it might make sense to publish mdn-data v3 such that it extracts the data from w3c/webref and merely presents it in the current format. But I'm not sure what the advantage of mdn-data's representation is in comparison to w3c/webref?

[caugner]

@yarusome Can you please take a look at my previous comment?