chore: add dependabot

[itamm15]

I am not a big fan of Dependabot (I prefer renovate), but it seems fine to have it there.

[patatoid]

There is no mix.lock file within the package, will this still work?

[itamm15]

Hey @patatoid! Do you mean within the dependabot.yaml? If so, then yes, that should work.
I just noticed that there is no mix.lock file in the repo (it is ignored via .gitignore). Is there any particular reason for that? Without `mix. lock ' file, the dependabot might not work correctly for minor updates, afair.

[patatoid]

@itamm15 there is no mix.lock because the library is to be integrated to existing projects. It helps to avoid conflicts with them.

Only major versions of the dependencies require an upgrade to be up to date. I am not sure dependabot is of any help here. If there are any, the best is to open a pull request depending on the needs.

[itamm15]

Hmm, I am not sure I get it? 🤔 Looking at other libs, like credo, ecto or gettext, they all have the mix.lock file.

[patatoid]

They may have no running applications, having a mix.lock file conflicts with the main application in my remembering.