[v.0.19.0] Scope default namespaces

Key changes

• Added capability to configure scope default namespcaces (pr - #256).
• Added documentation for ElementCodecConfig (pr - #256).
• Updated dependency versions.

What's Changed

• Update fs2-core, fs2-io to 3.4.0 by @scala-steward in #254
• Update sbt-sonatype to 3.9.15 by @scala-steward in #255
• Add scope default namespaces + more documentation for ElementCodecConfig by @valentiay in #256

Full Changelog: v0.18.0...v0.19.0