Not exactly a Sublime ‘package’, but have you checked this solution?
Also, at the lower-right of the Sublime, there is an “Open all with current extension as…” option if you click on the text that reads “Plain Text”.
Not exactly a Sublime ‘package’, but have you checked this solution?
Also, at the lower-right of the Sublime, there is an “Open all with current extension as…” option if you click on the text that reads “Plain Text”.