Provide a JSON Schema definition

[flother]

Typedoc is able to output a JSON schema. We should look into including it in the docs site, in order to be able to use it as a schema to support auto-complete and linting in IDEs. For example, if it would allow us to write something like this:

{
  "$schema": "https://jsfkit.github.io/types/schema.json",
  "name": "foo.xlsx",
  "sheeets": [
    {
      "name": "Sheet1",
      "cells": {
        "A1": { "v": 10 }
      }
    }
  ],
  "names": [],
  "calculationProperties": {
    "iterate": false,
    "iterateCount": 100,
    "iterateDelta": 0.001,
    "epoch": 1900
  }
}

And get IDEs to complain about the missing properties and misspelling of sheeets, then we're onto a good thing.

[flother]

Turns out Typedoc's JSON output isn't actually JSON Schema. But we could use typescript-json-schema to convert the TypeScript types into a JSON schema:

npx typescript-json-schema tsconfig.json Workbook --noExtraProps --required --out jsf-schema.json

For starters we just need to include this in GitHub Pages deployment somehow. We could worry about versioning the schema later.

I did need to change the cells property on the Worksheet and ExternalWorksheet types. From:

types/src/types/worksheets/worksheet.ts

Line 14 in 54236a0

cells: Record<CellId, Cell>;

types/src/types/external_worksheet.ts

Line 18 in 54236a0

cells: Record<CellId, Cell>;

To:

  cells: {
    [key: CellId]: Cell;
  };

Without this change, typescript-json-schema wasn't outputting anything useful for cells and JSF files weren't valid. With it, it enforces string keys (but no pattern restriction) with Cell objects as values.