tsconfig: Enable allowImportingTsExtensions.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

tsconfig.json

@@ -4,6 +4,7 @@
     "target": "esnext",
     "module": "esnext",
     "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
     "esModuleInterop": true,
     "paths": {
       // https://github.com/getsentry/sentry-electron/issues/957

xo.config.cjs

@@ -2,6 +2,11 @@
 
 module.exports = {
   prettier: true,
+  settings: {
+    n: {
+      typescriptExtensionMap: [],
+    },
+  },
   rules: {
     "@typescript-eslint/no-dynamic-delete": "off",
     "arrow-body-style": "error",