Add changelog file

Author: greenrobot-team

CHANGELOG.md

@@ -0,0 +1,59 @@
+# Changelog
+
+Notable changes to the ObjectBox Swift library.
+
+For more insights into what changed in the ObjectBox C++ core, [check the ObjectBox C changelog](https://github.com/objectbox/objectbox-c/blob/main/CHANGELOG.md).
+
+## 4.0.0 - 2024-07-22
+
+**ObjectBox now supports [Vector Search](https://docs.objectbox.io/ann-vector-search)** to enable efficient similarity searches.
+
+This is particularly useful for AI/ML/RAG applications, e.g. image, audio, or text similarity. Other use cases include semantic search or recommendation engines.
+
+Create a Vector (HNSW) index for a floating point vector property. For example, a `City` with a location vector:
+
+```swift
+// objectbox: entity
+class City {
+
+    // objectbox:hnswIndex: dimensions=2
+    var location: [Float]?
+    
+}
+```
+
+Perform a nearest neighbor search using the new `nearestNeighbors(queryVector, maxCount)` query condition and the new "find with scores" query methods (the score is the distance to the query vector). For example, find the 2 closest cities:
+
+```swift
+let madrid = [40.416775, -3.703790]
+let query = try box
+        .query { City.coordinates.nearestNeighbors(queryVector: madrid, maxCount: 2) }
+        .build()
+let closest = query.findWithScores()[0].object
+```
+
+For an introduction to Vector Search, more details and other supported languages see the [Vector Search documentation](https://docs.objectbox.io/ann-vector-search).
+
+- Built with Xcode 15.0.1 and Swift 5.9.
+- The generator now displays an error when using an index on a property type that can not be indexed.
+- Update to [ObjectBox C 4.0.1](https://github.com/objectbox/objectbox-c/releases/tag/v4.0.1).
+
+## 2.0.0 - 2024-05-15
+
+- Built with Xcode 15.0.1 and Swift 5.9.
+- Support creating file-less in-memory databases, e.g. for caching and testing. To create one instead of a directory path pass `memory:` together with an identifier string when creating a `Store`:
+
+  ```swift
+  inMemoryStore = try Store(directoryPath: "memory:test-db");
+  ```
+
+  See the `Store` documentation for details.
+- Change `Store.closeAndDeleteAllFiles()` to support deleting an in-memory database.
+- Removed some deprecated APIs:
+  - Removed `findIntegers()` for property query, replaced by `find()`.
+  - Removed `find()` of `Box`, replaced by `all()`.
+- Update to [ObjectBox C 4.0.0](https://github.com/objectbox/objectbox-c/releases/tag/v4.0.0).
+
+## Previous versions
+
+See the [changelog in the documentation](https://swift.objectbox.io/).

README.md

@@ -160,6 +160,10 @@ Here's a list of ObjectBox releases, and the Swift versions they were compiled w
 
 This might be relevant, e.g. when using Carthage. For various reasons, we recommend using the latest version.
 
+## Changelog
+
+For notable and important changes in new releases, read the [changelog](CHANGELOG.md).
+
 ## Development
 
 The source code for ObjectBox's Swift binding can be found [in the Source folder](Source/README.md) of this repository.