Use `refs/tags/v${version}` in `fetchFromGitHub`.

[GaetanLepage]

When using the fetchFromGitHub fetcher, it is recommended to prefix the rev with refs/tags to prevent branch-tag mismatch.

Currently, nix-init generates

src = fetchFromGitHub {
  owner = "foo";
  repo = "bar";
  rev = "refs/tags/${version}";  # or "refs/tags/v${version}"
  hash = "...";
};

Ideally, it should generate:

src = fetchFromGitHub {
  owner = "foo";
  repo = "bar";
  tag = version;  # or "v${version}"
  hash = "...";
};

[Moraxyc]

It's better to let nix-init generate tag

src = fetchFromGitHub {
  owner = "foo";
  repo = "bar";
  tag = version;  # or "v${version}"
  hash = "...";
};

[GaetanLepage]

It's better to let nix-init generate tag

Definitely, I inverted "before" and "after". I edited the initial message.

[eclairevoyant]

The original message still mentions rev instead of tag for the "after" case, btw :)

[GaetanLepage]

The original message still mentions rev instead of tag for the "after" case, btw :)

Wow, that was harder than expected... Fixed