Add Handlebars support

[danielbankhead]

Adding "*.hbs": "html"/"*.handlebars": "html" to "files.associations" breaks compatibility with existing Handlebars extensions. Since Handlebars can be used as a superset of HTML this change should not be a problem.

[abusaidm]

hello @danielbankhead ,
Are you saying adding this extension will cause Handlebars extensions to break?
Can you elaborate please.

Thank you.

[danielbankhead]

Hey @abusaidm,

I was able to solve my issue. I was updating files.associations in my settings.json per the FAQ instructions found on the Marketplace README, which didn't help since changing the Handlebars extension (*.hbs) from 'handlebars' to 'html' broke compatibility with existing packages that expect 'language' === 'handlebars', such as andrejunges.Handlebars.

However, the updated README on this repo links to a helpful comment that solved my issue. Perhaps an update on the Marketplace README to avoid confusion?

Thanks