C#: Update changenotes

Author: calumgrant

change-notes/1.25/analysis-csharp.md

@@ -18,10 +18,13 @@ The following changes in version 1.25 affect C# analysis in all applications.
 
 ## Changes to code extraction
 
+* Index initializers, of the form `{ [1] = "one" }`, are extracted correctly. Previously, the kind of the
+  expression was incorrect, and the index was not extracted.
+
 ## Changes to libraries
 
 * The class `UnboundGeneric` has been refined to only be those declarations that actually
-  have type parameters. This means that non-generic nested types inside construced types,
+  have type parameters. This means that non-generic nested types inside constructed types,
   such as `A<int>.B`, no longer are considered unbound generics. (Such nested types do,
   however, still have relevant `.getSourceDeclaration()`s, for example `A<>.B`.)