Clarify the meaning of `===` for non-object types; reorder sections to put more important information to the front.
Clarify the meaning of `===` for non-object types; reorder sections
to put more important information to the front.

Inspired by https://stackoverflow.com/questions/48472082/how-to-explain-these-kotlin-codes-about-int-type

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