Exclude node_modules from TS compilation

TypeScript excludes `node_modules` by default (among other directories)
if you don't specify `exclude` in the TS config, but if you specify
`exclude`, then you need to make to explicitly list `node_modules`.

tsconfig.json

@@ -12,5 +12,5 @@
     "strict": true,
     "target": "es2020"
   },
-  "exclude": ["./dist/**/*"]
+  "exclude": ["./dist", "./node_modules"]
 }