Update docs for 3.0 release

Docs/ChangeLog-3x.md

@@ -9,11 +9,12 @@ clocked at 4.2 GHz, running astcenc using AVX2 and 6 threads.
 <!-- ---------------------------------------------------------------------- -->
 ## 3.0
 
-**Status:** ETA, August 2021
+**Status:** June 2021
 
-The 3.0 alpha release is a preview release for the 3.x series. This series is
-aiming to provide a major update to the codec with more experimental changes
-than we could make with the 2.x series.
+The 3.0 release is the first in a series of updates to the compressor that are
+making more radical changes than we felt we could make with the 2.x series.
+The primary goals of the 3.x series are to keep the image quality ~static or
+better compared to the 2.5 release, but continue to improve performance.
 
 Reminder for users of the library interface - the API is not designed to be
 binary compatible across versions, and this release is not compatible with
@@ -22,8 +23,14 @@ updated `astcenc.h` header.
 
 * **General:**
   * **Feature:** The code has been significantly cleaned up, with improved
-    API documentation, function and variable naming conventions, and comments.
+    comments, API documentation, function naming, and variable naming.
 * **Core API:**
+  * **API Change:** The core APIs for `astcenc_compress_image()` and for
+    `astcenc_decompress_image()` now accept swizzle structures by `const`
+    pointer, instead of pass-by-value.
+  * **API Change:** Calling the `astcenc_compress_reset()` and the
+    `astcenc_decompress_reset()` functions between images is no longer required
+    if the context was created for use by a single thread.
   * **Feature:** New heuristics have been added for controlling when to search
     beyond 2 partitions and 1 plane, and when to search beyond 3 partitions and
     1 plane. The previous `tune_partition_early_out_limit` config option has
@@ -32,27 +39,24 @@ updated `astcenc.h` header.
     `tune_3_partition_early_out_limit_factor`. See command line help for more
     detailed documentation.
   * **Feature:** New heuristics have been added for controlling when to use
-    2 planes. The previous `tune_two_plane_early_out_limit` has been renamed to
-    `tune_2_plane_early_out_limit_correlation`. See command line help for more
-    detailed documentation.
+    dual weight planes. The previous `tune_two_plane_early_out_limit` has been
+    renamed to`tune_2_plane_early_out_limit_correlation`. See command line help
+    for more detailed documentation.
   * **Feature:** Support for using dual weight planes has been restricted to
-    single partition blocks; it rarely helps blocks with 2+ partitions and
-    takes considerable compression search time.
-  * **API Change:** The core APIs for `astcenc_compress_image()` and for
-    `astcenc_decompress_image()` now accept swizzle structures by `const`
-    pointer, instead of pass-by-value.
-  * **API Change:** Calling the `astcenc_compress_reset()` and the
-    `astcenc_decompress_reset()` functions between images is no longer required
-    if the context was created for use by a single thread.
+    single partition blocks; it rarely helps blocks with 2 or more partitions
+    and takes considerable compression search time.
 
 ### Performance:
 
-The current performance and image quality for the 3.0 development build vs the
-stable 2.5 release is shown below.
+Key for charts:
 
 * Color = block size (see legend).
 * Letter = image format (N = normal map, G = greyscale, L = LDR, H = HDR).
 
+**Absolute performance vs 2.5 release:**
+
+![Absolute scores 3.0 vs 2.5](./ChangeLogImg/absolute-2.5-to-3.0.png)
+
 **Relative performance vs 2.5 release:**
 
-![Relative scores 3.0-develop vs 2.5](./ChangeLogImg/relative-main-to-2.5.png)
+![Relative scores 3.0 vs 2.5](./ChangeLogImg/relative-2.5-to-3.0.png)

README.md

@@ -58,12 +58,15 @@ from 0.89 bits/pixel up to 8 bits/pixel.
 Release build binaries for the `astcenc` stable releases are provided in the
 [GitHub Releases page][3].
 
-**Latest stable release:** 2.5
+**Latest 3.x stable release:** 3.0
+* Change log: [3.x series](./Docs/ChangeLog-3x.md)
+
+**Latest 2.x stable release:** 2.5
 * Change log: [2.x series](./Docs/ChangeLog-2x.md)
 
-**Latest development release:** 3.0-develop
+**Latest development release:** 3.1-develop
 * Change log: [3.x series](./Docs/ChangeLog-3x.md)
-* Roadmap: [3.0 and beyond](./Docs/Roadmap.md)
+* Roadmap: [Ideas ...](./Docs/Roadmap.md)
 
 Binaries are provided for 64-bit builds on Windows, macOS, and Linux. The
 builds of the astcenc are provided as multiple binaries, each tuned for a