Merge pull request swiftlang#37104 from benrimmington/changelog-auto-toc

Author: swift-ci

CHANGELOG.md

@@ -1,39 +1,16 @@
 CHANGELOG
 =========
 
-<details>
-<summary>Note: This is in reverse chronological order, so newer entries are added to the top.</summary>
-
-| Version                | Released   | Toolchain   |
-| :--------------------- | :--------- | :---------- |
-| [Swift 5.5](#swift-55) |            |             |
-| [Swift 5.4](#swift-54) | 2021-04-26 | Xcode 12.5  |
-| [Swift 5.3](#swift-53) | 2020-09-16 | Xcode 12.0  |
-| [Swift 5.2](#swift-52) | 2020-03-24 | Xcode 11.4  |
-| [Swift 5.1](#swift-51) | 2019-09-20 | Xcode 11.0  |
-| [Swift 5.0](#swift-50) | 2019-03-25 | Xcode 10.2  |
-| [Swift 4.2](#swift-42) | 2018-09-17 | Xcode 10.0  |
-| [Swift 4.1](#swift-41) | 2018-03-29 | Xcode 9.3   |
-| [Swift 4.0](#swift-40) | 2017-09-19 | Xcode 9.0   |
-| [Swift 3.1](#swift-31) | 2017-03-27 | Xcode 8.3   |
-| [Swift 3.0](#swift-30) | 2016-09-13 | Xcode 8.0   |
-| [Swift 2.2](#swift-22) | 2016-03-21 | Xcode 7.3   |
-| [Swift 2.1](#swift-21) | 2015-10-21 | Xcode 7.1   |
-| [Swift 2.0](#swift-20) | 2015-09-17 | Xcode 7.0   |
-| [Swift 1.2](#swift-12) | 2015-04-08 | Xcode 6.3   |
-| [Swift 1.1](#swift-11) | 2014-12-02 | Xcode 6.1.1 |
-| [Swift 1.0](#swift-10) | 2014-09-15 | Xcode 6.0   |
-
-</details>
+_**Note:** This is in reverse chronological order, so newer entries are added to the top._
 
 Swift 5.5
 ---------
 
 * [SE-0306][]:
 
-	Swift 5.5 includes support for actors, a new kind of type that isolates its instance data to protect it from concurrent access. Accesses to an actor's instance declarations from outside the must be asynchronous:
+  Swift 5.5 includes support for actors, a new kind of type that isolates its instance data to protect it from concurrent access. Accesses to an actor's instance declarations from outside the must be asynchronous:
 
-	```swift
+  ```swift
   actor Counter {
     var value = 0
 
@@ -46,7 +23,7 @@ Swift 5.5
     print(await counter.value) // interaction must be async
     await counter.increment()  // interaction must be async
   }
-	```
+  ```
 
 * The determination of whether a call to a `rethrows` function can throw now considers default arguments of `Optional` type.
 
@@ -192,11 +169,11 @@ Swift 5.5
 
   The "for" loop can be used to traverse asynchronous sequences in asynchronous code:
 
-	```swift
+  ```swift
   for try await line in myFile.lines() {
     // Do something with each line
   }
-	```
+  ```
 
   Asynchronous for loops use asynchronous sequences, defined by the protocol
   `AsyncSequence` and its corresponding `AsyncIterator`.