Setup automated releases

[jacques-n]

@cpcloud and I have been discussing introducing automated releases/release notes and starting to version things. We should get this going since other projects would be much better off depending on a released set of substrait proto definitions, etc as opposed to using a git hash.

[cpcloud]

Yep, I can look into this.

[winningsix]

Any more details for this? One quick question around this, for a Substrait dependent project, will Substrait be linked as a Git submodule or include protobuf there?

[jacques-n]

I think this will depend on the language. For things like Javascript, Java and, python I think we should publish compiled files. For c and c++ I think we should probably publish a tgz with the proto files. What do others think?

[FelixYBW]

Do we have plan to create and release the helper tools for each language as well? Like substrait_plan_builder etc.? The builder function will be useful to create and test substriat plans consumers. If so for c/c++ we may need to publish a library as well in future.

[jacques-n]

Do we have plan to create and release the helper tools for each language as well? Like substrait_plan_builder etc.?

Yes, I think we should do that. I'm definitely trying to provide that as part of the java patch I'm working on.