docs: revert `Parcelable` experimentality (#1358)
docs: revert `Parcelable` experimentality (#1358)

* docs: reverted the docs about non-experimental Parcelable implementation generator

* docs: reverted the docs about non-experimental Parcelable implementation generator

* fix: removed an asterisk

JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,hltj/kotlin-web-site-cn,hltj/kotlin-web-site-cn,hltj/kotlin-web-site-cn,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,hltj/kotlin-web-site-cn