Add missing TypeScript interfaces and properties

[kossnocorp]

Hey! I started adopting deno doc for date-fns documentation generation. Thank you a lot for the outstanding tool!

After running deno doc --json against date-fns and then type checking the resulting JSON, I found that some TypeScript interfaces and properties were missing, so I added them.

I confirmed that the type changes fix all the problems for date-fns by manually updating node_modules/@deno/doc/types.d.ts.

---

Here's the script I used to generate and type check the docs JSON: buildDocs.sh.

You can see the TypeScript errors I get: logs.txt.

Here's the source code I got as the result: docs.ts (I apologize for a OneDrive link. GitHub Gist was throwing 500 on an attempt to upload ~200K LoC file).

You can also reproduce the problem if you clone the date-fns repo and run:

git submodule update --recursive --init --remote
pnpm install
cd submodules/docs
DATE_FNS_DIR="../.." ./scripts/buildDocs.sh

You will find the docs.json at submodules/docs/tmp/docs.json and the TypeScript code at submodules/docs/tmp/docs.ts.

You can also rerun the tsc (after running the buildDocs.sh first):

cd submodules/docs
pnpm tsc --noEmit --skipLibCheck --module NodeNext --moduleResolution NodeNext tmp/docs.ts

---

I made missing properties optional to avoid breaking any libraries that depend on it. I also couldn't figure out the proper constructors interface, so I made it unknown[].

Furthermore, I also added the Docs interface to represent the root data structure of the JSON.

[CLAassistant]

All committers have signed the CLA.