refresh freatures description of HuaweiCloud OBS Adapter for Hadoop Support

Refresh freatures description of HuaweiCloud OBS Adapter for Hadoop Support, such as :
rename, Append , hflush&hsync support.

link : hadoop/hadoop-cloud-storage-project/hadoop-huaweicloud/src/site/markdown/index.md

Features
Present a hierarchical HDFS file system by implementing the standard Hadoop FileSystem interface.
In hadoop, Read and write data stored in a HuaweiCloud OBS bucket.
Can act as a source of data in a MapReduce job, or a sink.
Support multipart upload for a large file.
Reference file system paths using URLs using the obs scheme.
Uses HuaweiCloud OBS’s Java SDK with support for latest OBS features and authentication schemes.
For OBS 'Parallel file system bucket'(Posix), support rename with atomic semantics, Append, hflush&hsync.
For OBS 'Parallel file system bucket'(Posix), Provide trash mechanism and quickly delete, which using rename and lifecircle of OBS bucket.
Tested for scale.