Update CHANGELOG for v0.1.0b8 release (#160)

Release changelog for v0.1.0b8.

## Changes included in this release

### Added
- Batch API: `client.batch` namespace for deferred-execution batch
operations (#129)
- Batch DataFrame integration: `client.batch.dataframe` namespace (#129)
- `client.records.upsert()` and `client.batch.records.upsert()` with
alternate-key support (#129)
- QueryBuilder: `client.query.builder()` with fluent API and composable
filter expressions (#118)
- Memo/multiline column type support in `client.tables.create()` and
`client.tables.add_columns()` (#155)

### Changed
- Picklist label resolution now uses a single bulk API call per table
with 1-hour TTL cache (#154)

### Fixed
- `client.query.sql()` now paginates and returns all rows instead of
truncating at 5,000 (#157)
- Alternate key fields no longer merged into `UpsertMultiple` request
body (#129)
- Docstring type annotations corrected for Microsoft Learn compatibility
(#153)

---------

Co-authored-by: Abel Milash <abelmilash@microsoft.com>

Author: abelmilash-msft

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.1.0b8] - 2026-04-10
+
 ### Added
 - Batch API: `client.batch` namespace for deferred-execution batch operations that pack multiple Dataverse Web API calls into a single `POST $batch` HTTP request (#129)
 - Batch DataFrame integration: `client.batch.dataframe` namespace with pandas DataFrame wrappers for batch operations (#129)
@@ -108,7 +110,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Comprehensive error handling with specific exception types (`DataverseError`, `AuthenticationError`, etc.) (#22, #24)
 - HTTP retry logic with exponential backoff for resilient operations (#72)
 
-[Unreleased]: https://github.com/microsoft/PowerPlatform-DataverseClient-Python/compare/v0.1.0b7...HEAD
+[Unreleased]: https://github.com/microsoft/PowerPlatform-DataverseClient-Python/compare/v0.1.0b8...HEAD
+[0.1.0b8]: https://github.com/microsoft/PowerPlatform-DataverseClient-Python/compare/v0.1.0b7...v0.1.0b8
 [0.1.0b7]: https://github.com/microsoft/PowerPlatform-DataverseClient-Python/compare/v0.1.0b6...v0.1.0b7
 [0.1.0b6]: https://github.com/microsoft/PowerPlatform-DataverseClient-Python/compare/v0.1.0b5...v0.1.0b6
 [0.1.0b5]: https://github.com/microsoft/PowerPlatform-DataverseClient-Python/compare/v0.1.0b4...v0.1.0b5