v4.0.3
[SPARK-1564] [DOCS] Added Javascript to Javadocs to create badges for tags like :: Experimental ::
[SPARK-30654] Bootstrap4 docs upgrade
[SPARK-49456][DOCS] Fix hash fragment scrolling behavior on versioned Spark documentation
[SPARK-33166][DOC] Provide Search Function in Spark docs site
[SPARK-51104][DOC][FOLLOWUP] Self-host docsearch.min.css in Spark website
[SPARK-51128][DOC] Self host docsearch.min.css.map in Spark website
[SPARK-28752][BUILD][DOCS] Documentation build to support Python 3