add readme for emmylua_check

Author: CppCXY

crates/emmylua_check/README.md

@@ -0,0 +1,15 @@
+# EmmyLua Check
+
+a static check tool for Lua, written in Rust.
+
+## Installation
+
+```shell
+cargo install emmylua_check
+```
+
+## Usage
+
+```shell
+emmylua_check --help
+```