Test actual build output

This represents the production environment more than using `tsx`.

Also support was added for source maps and declaration maps.

.c8rc.json

@@ -1,4 +1,5 @@
 {
   "100": true,
+  "exclude": ["**/test.*"],
   "reporter": ["html", "lcov", "text"]
 }

.gitignore

@@ -1,7 +1,5 @@
 coverage/
 dist/
 node_modules/
-*.d.ts
-*.js
-*.log
 *.tgz
+*.tsbuildinfo