v4.2.0
[SPARK-29052][DOCS][ML][PYTHON][CORE][R][SQL][SS] Create a Migration Guide tap in Spark documentation
[SPARK-25584][ML][DOC] datasource for libsvm user guide
[MINOR][DOCS] Fix various broken links and link anchors
[SPARK-54509][DOCS] Add Documentation for Spark Data Source V2
[SPARK-49378][DOCS][SS] Break apart the Structured Streaming Programming Guide