This one seemed like a really weird code until I saw that the categories were "fun" and "programming", and not "cryptography". So I just searched the web for "Hodor esoteric programming language" or something similar and quickly found hodor-lang.
Ok, so I guess we're doing this. You can easily install it with npm:
npm install -g hodor-lang
And then run the code with:
hodor challenge.hd
Which produces the following output:
Awesome, you decoded Hodors language!
As sis a real h4xx0r he loves base64 as well.
SFYxOXtoMDFkLXRoMy1kMDByLTQyMDQtbGQ0WX0=
So we got the flag encoded as base64, which we can decode like this:
echo SFYxOXtoMDFkLXRoMy1kMDByLTQyMDQtbGQ0WX0= | base64 --decode
And we get the solution: HV19{h01d-th3-d00r-4204-ld4Y}