readme: modify project description

update license holder

LICENSE-MIT

@@ -1,4 +1,4 @@
-Copyright 2020 Luo Jia
+Copyright 2020-2022 RustSBI Team
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

LICENSE-MULAN

@@ -52,7 +52,7 @@
 
 3，请将如下声明文本放入每个源文件的头部注释中。
 
-Copyright (c) 2020 Luo Jia
+Copyright (c) 2020-2022 RustSBI Team
 
 RustSBI is licensed under Mulan PSL v2. You can use this software according to the terms and conditions of the Mulan PSL v2. You may obtain a copy of Mulan PSL v2 at: http://license.coscl.org.cn/MulanPSL2 
 

README.md

@@ -1,6 +1,6 @@
 # RustSBI
 
-RISC-V Supervisor Binary Interface ([SBI](https://github.com/riscv-non-isa/riscv-sbi-doc/)) implementation in Rust; runs on M-mode.
+RISC-V Supervisor Binary Interface ([SBI](https://github.com/riscv-non-isa/riscv-sbi-doc/)) library in Rust; runs on M-mode or HS mode.
 
 [![crates.io](https://img.shields.io/crates/v/rustsbi.svg)](https://crates.io/crates/rustsbi)
 [![Documentation](https://docs.rs/rustsbi/badge.svg)](https://docs.rs/rustsbi)