feat(docs): Add TS type gen, metadata JSON gen

* Generate TS types from new hardware metadata schema.
* Aggregate all hw metadata YAML into one aggregate JSON
  file for consumption by others.

docs/src/hardware-metadata-collection-plugin/index.js

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+var PrebuildPlugin = require("prebuild-webpack-plugin");
+const fs = require("fs");
+const yaml = require("js-yaml");
+const glob = require("glob");
+const { compile, compileFromFile } = require('json-schema-to-typescript');
+
+function generateHardwareMetadataAggregate() {
+  glob("../app/boards/**/*.zmk.yml", (error, files) => {
+    const aggregated = files.flatMap(f => yaml.safeLoadAll(fs.readFileSync(f, "utf8")));
+    fs.writeFileSync("src/data/hardware-metadata.json", JSON.stringify(aggregated));
+  });
+}
+
+module.exports = function () {
+  return {
+    name: "hardware-metadata-collection-plugin",
+    configureWebpack() {
+      return {
+        plugins: [
+          new PrebuildPlugin({
+            build: generateHardwareMetadataAggregate,
+          }),
+        ],
+      };
+    },
+  };
+};