Update RELEASE_NOTES.md for 1.5.2-beta2 (#219)

### Changes
* Update RELEASE_NOTES.md
* Modernize Directory.Build.props to include NuGet package README, license, and icon

RELEASE_NOTES.md

@@ -1,3 +1,33 @@
+#### 1.5.2-beta2 April 14 2023 ###
+
+> **NOTE: Database schema changes**
+> 
+> 1.5.2-beta1 package should be considered as deprecated. If you experimented with 1.5.2-beta1, you will need to drop existing persistence tables and recreate them using 1.5.2-beta2
+
+* [Fix event journal table and tag table constraints and indices](https://github.com/akkadotnet/Akka.Persistence.Sql/pull/211)
+* [Fix snapshot table constraints and indices](https://github.com/akkadotnet/Akka.Persistence.Sql/pull/216)
+
+This beta version introduces database schema optimization to:
+* Improve the tag table based query performance, without compromising overall persistence performance.
+* Improve inter-compatibility with other SQL persistence plugins. 
+
+**Tag Query Benchmark**
+
+Benchmark is performed on a worst possible scenario:
+* Event journal table with 3 million row entries
+* Tagged events near the end of the table
+
+|        Tag Count |  TagMode |         Mean |      Error |     StdDev |
+|-----------------:|--------- |-------------:|-----------:|-----------:|
+|               10 |      Csv | 1,746.621 ms | 27.8946 ms | 29.8469 ms |
+|              100 |      Csv | 1,724.465 ms | 25.4638 ms | 23.8189 ms |
+|             1000 |      Csv | 1,723.063 ms | 26.2311 ms | 24.5366 ms |
+|            10000 |      Csv | 1,873.467 ms | 26.1173 ms | 23.1523 ms |
+|               10 | TagTable |     3.201 ms |  0.0633 ms |  0.1479 ms |
+|              100 | TagTable |     5.163 ms |  0.1018 ms |  0.1358 ms |
+|             1000 | TagTable |    25.545 ms |  0.4952 ms |  0.4864 ms |
+|            10000 | TagTable |   441.877 ms |  3.5410 ms |  2.9569 ms |
+
 #### 1.5.2-beta1 April 12 2023 ###
 
 > **NOTE: This beta release is intended for greenfield projects only.**