chore(release): bump version to 1.8.1

- Update CHANGELOG.md for version 1.8.1 release
- Update plugin.json to version 1.8.1
- Remove unnecessary blank lines and old entries in CHANGELOG.md

Author: terwer

CHANGELOG.md

@@ -1,17 +1,12 @@
 # Changelog
 
 ## [1.8.1](https://github.com/terwer/siyuan-plugin-importer/compare/v1.8.0...v1.8.1) (2025-06-18)
-
-
 ### Bug Fixes
-
 * **importer:** optimize styles and improve import settings ([7615111](https://github.com/terwer/siyuan-plugin-importer/commit/7615111b970012086661e1dbabf388fecd88da0e))
-
 ## [1.8.0](https://github.com/terwer/siyuan-plugin-importer/compare/v1.7.0...v1.8.0) (2025-06-15)
 ### Features
 * **importsetting:** add tab navigation for settings and test ([57ef273](https://github.com/terwer/siyuan-plugin-importer/commit/57ef273f8faaa7b63daf4f59686dee56e2330c11))
 * **import:** support direct import of md files ([6842f00](https://github.com/terwer/siyuan-plugin-importer/commit/6842f0059fb87a80d2247844817b6c6a74624972))
-### Bug Fixes
 * 修复文件检测不生效问题 ([b608ac2](https://github.com/terwer/siyuan-plugin-importer/commit/b608ac2f0bac896dfe51501cf42e61d7b5a2989e))
 ### Code Refactoring
 * remove unused components and update styles ([6b29a68](https://github.com/terwer/siyuan-plugin-importer/commit/6b29a68b3ed70cf4fe92b2ef7ece87cd412d35c2))
@@ -82,4 +77,4 @@
 * 导入工具第一个版本 ([1fc739b2](https://github.com/terwer/siyuan-plugin-importer/commit/1fc739b676ba51460c7f57e4e22c00869517b74f))
 * 插件最小化运行单位 ([155a825](https://github.com/terwer/siyuan-plugin-importer/commit/155a825461bf447d45083329ccce9eb93b3857d6))
 * 新增kernelapi ([80ca482](https://github.com/terwer/siyuan-plugin-importer/commit/80ca4829e5949c871ddaacad2e6fced1771bd336))
-* **main:** release 1.0.0 ([74258ce](https://github.com/terwer/siyuan-plugin-importer/commit/74258ce418a45bd64c7a4c2b947508a842691605))
+* **main:** release 1.0.0 ([74258ce](https://github.com/terwer/siyuan-plugin-importer/commit/74258ce418a45bd64c7a4c2b947508a842691605))

plugin.json

@@ -2,7 +2,7 @@
   "name": "siyuan-importer",
   "author": "terwer",
   "url": "https://github.com/terwer/siyuan-plugin-importer",
-  "version": "1.8.0",
+  "version": "1.8.1",
   "minAppVersion": "2.9.2",
   "backends": [
     "windows",