add 'neovim' to default labels if empty

[teto]

I suppose here :

luarocks-tag-release/bin/luarocks-tag-release.lua

Line 168 in e3a7af1

if not args.labels or #args.labels == 0 then

This way most neovim plugins using this action could eventually come up at https://luarocks.org/labels/neovim
(once luarocks/luarocks-site#188 is fixed).

[mrcjkb]

🤔 I would like to keep this compatible with non-neovim packages, if possible. So perhaps just adding neovim as a default label in action.yaml would be better - so it can be disabled if unwanted.

[teto]

I would like to keep this compatible with non-neovim packages

Makes sense, I had not realized that (considerign the orgname maybe "nvim-neorocks" ;) ). Also the scripts picks up the repository labels, which should probably contain "neovim", so maybe it's just a matter of adding it to the doc or have an heuristic that detects the repo is a neovim plugin and warns the user to set "neovim" as a repo label when missing.