Mark SE-0383 as implemented in Swift 5.10 (#2233)

* Mark SE-0383 as implemented in Swift 5.10

* Add an upcoming feature flag for SE-0383.

Author: hborla

proposals/0383-deprecate-uiapplicationmain-and-nsapplicationmain.md

@@ -3,7 +3,8 @@
 * Proposal: [SE-0383](0383-deprecate-uiapplicationmain-and-nsapplicationmain.md)
 * Authors: [Robert Widmann](https://github.com/codafi)
 * Review Manager: [John McCall](https://github.com/rjmccall)
-* Status: **Accepted**
+* Status: **Implemented (Swift 5.10)**
+* Upcoming Feature Flag: `DeprecateApplicationMain`
 * Implementation: [PR 62151](https://github.com/apple/swift/pull/62151)
 * Review: ([pitch](https://forums.swift.org/t/deprecate-uiapplicationmain-and-nsapplicationmain/61493)) ([review](https://forums.swift.org/t/se-0383-deprecate-uiapplicationmain-and-nsapplicationmain/62375)) ([acceptance](https://forums.swift.org/t/accepted-se-0383-deprecate-uiapplicationmain-and-nsapplicationmain/62645))