Add ARTIFACTS.md

[imheresamir]

What does this PR do?

Adds ARTIFACTS.md to provide a list of all artifact types that we build and distribute with the following details:

• Type of artifact produced for release (e.g. JAR, Rubygem, etc).
• Distribution location for the artifact (e.g. GitHub releases, rubygems.org, etc), with link.
• Whether it's a manual or automatic process to create the artifact

What ticket does this PR close?

Resolves #228

Checklists

Change log

• [ ] The CHANGELOG has been updated, or
• [x] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [x] The changes in this PR do not require tests

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR, and/or there is a follow-on issue to update docs, or
• [x] This PR does not require updating any documentation

Release PRs

If you are preparing for a release, are the following items complete?

• [ ] The PR title / description clearly state the suite release version.
• [ ] The Jenkins dashboard shows no ongoing build failures for any included components.
• [ ] The PR includes a link to a markdown release notes draft - this can be generated by running:

   summon -p keyring.py   --yaml 'GITHUB_TOKEN: !var github/api_token' \
     ./parse-changelogs \
     -v {suite-version} \
     -t release \
     -o RELEASE_NOTES.md

• [ ] The PR includes PM-approved "What's new" text.