[skip ci] Update README.md (#896)

* Update README.md

* [skip ci] Add IVFLAT links

* [skip ci] Minor

docs/README.md

@@ -16,8 +16,10 @@ The following is a list of existing test reports:
 
 - [IVF_SQ8](test_report/milvus_ivfsq8_test_report_detailed_version.md)
 - [IVF_SQ8H](test_report/milvus_ivfsq8h_test_report_detailed_version.md)
+- [IVFLAT](test-report/ivfflat_test_report_en.md)
 
 To read the CN version of these reports:
 
 - [IVF_SQ8_cn](test_report/milvus_ivfsq8_test_report_detailed_version_cn.md)
 - [IVF_SQ8H_cn](test_report/milvus_ivfsq8h_test_report_detailed_version_cn.md)
+- [IVFLAT_cn](test-report/ivfflat_test_report_cn.md)