`print` and `PrintVisitor` types are not declared in index type definition file

[M-Nasab]

The print and PrintVisitor functions are exported from the library index file but their types are not declared in the index type declaration file.

This causes some problems when trying to import these functions and use them with typescript.

[jaylinski]

Exception and other types are also missing: https://github.com/handlebars-lang/handlebars-parser/blob/v2.1.0/lib/index.js