Publish our fork

[julienrf]

Here is the plan I suggest following:

• Create our main branch scylla-4.x, describing the fork motivation and goals (see e.g. in my fork)
• Rename package organization to com.scylladb and artifact to spark-scylladb-connector
• Rename this repository to spark-scylladb-connector
• Merge our branch feature/track-token-ranges-3.5.0 into scylla-4.x and document that feature in the README Update README (document added features, update compatibility matrix) #8
• Set up the release process (requires to set secrets in this repository to connect to Sonatype) Add release workflow #10
• Release version 4.0.0
• Use it in ScyllaDB Migrator Use published releases of spark-scylladb-connector scylla-migrator#209

[tarzanek]

#7
was done, but it's not documented in README (that we added savepoints)