Migrate electron files to typescript (#267)

- Switches electron src files to typescript with minimum typing required
for build
- Adds webpack-merge for shared typescript build config and jsdoc types
- Minor README changes

---------

Co-authored-by: emma <hi@emma.cafe>

src/electron-preload.ts

@@ -0,0 +1,67 @@
+/*eslint-env node */
+
+import { CollectionLoader } from "@webrecorder/wabac/src/loaders";
+
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const { ipcRenderer, contextBridge } = require("electron");
+
+contextBridge.exposeInMainWorld("electron", { IS_APP: true });
+
+const dbs = {};
+
+const loader = new CollectionLoader();
+
+/**
+ *
+ * @param {string} name
+ * @returns
+ */
+async function getColl(name) {
+  if (!dbs[name]) {
+    dbs[name] = await loader.loadColl(name);
+    await dbs[name].initing;
+  }
+
+  return dbs[name];
+}
+
+/**
+ * @param {string} name
+ * @returns
+ */
+async function getDB(name) {
+  const coll = await getColl(name);
+  return coll.store;
+}
+
+/**
+ *
+ * @param {import("electron").IpcRendererEvent} event
+ * @param {*} request
+ * @param {*} coll
+ * @param {*} ts
+ * @param {*} channel
+ * @returns
+ */
+async function getResponse(event, request, coll, ts, channel) {
+  const db = await getDB(coll);
+
+  const req = { request, url: request.url, timestamp: ts };
+
+  const result = await db.getResource(req, "", { request });
+
+  if (!result) {
+    ipcRenderer.send(channel, 404);
+    return;
+  }
+
+  const headers = Object.fromEntries(result.headers.entries());
+
+  const buffer = await result.getBuffer();
+
+  ipcRenderer.send(channel, result.status, headers, buffer);
+}
+
+ipcRenderer.on("getresponse", getResponse);
+
+export { getDB, getColl, loader };