When a user downloads an existing project, the required runtimes won't be installed. As part of the process, they need to download it using wws runtimes install as other similar tools like NodeJS. We want to provide a hint about this behavior so wws doesn't fail and it shows useful information.

From now on, wws will look for missing runtimes when running the run command (default one). If there're missing runtimes, it will show a message and will ask users to install it using wws runtimes install. In the future, we will evaluate if installing missing runtimes should be part of the regular process.

In addition to that, now wws will ignore the extensions of not installed runtimes.

./wws .
⚠️  Required language runtimes are not installed. Some files may not be considered workers
⚠️  You can install the missing runtimes with: wws runtimes install
⚙️  Loading routes from: .
🗺  Detected routes:
🚀 Start serving requests at http://127.0.0.1:8080

It closes #69