docs: Add README

README.md

@@ -0,0 +1,27 @@
+# rimg
+
+## Build
+
+After installing Rust, run the below commands to build.
+
+```sh
+$ git clone https://github.com/Takashicc/rimg
+$ cd rimg
+$ cargo build --release
+$ ./target/release/rimg --version
+rimg 0.1.0
+```
+
+## Commands
+
+### Rename
+
+Rename files in each directory to sequential number.
+
+```sh
+$ ./target/release/rimg rename "~/test" -y
+2 directories will be executed
+There are no JPG files in test directory
+Renaming JPG files in xxx directory
+|############################################################| 24   /24    Renaming xxx
+```