As discussed in https://github.com/go-enry/go-enry/issues/54, this provides an
API for accessing a LanguageInfo struct which is populated with all the data
from the Linguist YAML source file. Functions are provided to access the
LanguageInfo by name or ID.
The other top-level functions like GetLanguageExtensions, GetLanguageGroup, etc.
could in principle be implemented using this structure, which would simplify the
code generation. But that would be a big change so I didn't do any of that.
Perhaps in the next major version something like that would make sense.
The Linguist-defined language IDs are important to our use case because they are
used as database identifiers. This adds a new generator to extract the language
IDs into a map and uses that to implement GetLanguageID.
Because one language has the ID 0, there is no way to tell if a language name is
found or not. If desired, we could add this by returning (string, bool) from
GetLanguageID. But none of the other functions that take language names do this,
so I didn't want to introduce it here.
