add guide to install as a cli

README.md

@@ -25,3 +25,21 @@ eval(&"++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.
 ```
 
 Also check out `examples/` directory
+
+## Using this as command-line interpreter
+There is an example `eval_file`, which you can compile to a standalone binary
+
+```sh
+cargo b --release --example=eval_file
+cd target/release/examples
+
+# those two are optional, they are needed to reduce the size of binary
+# its recommended but if they fail its no big deal
+strip eval_file
+upx eval_file
+
+cp eval_file /usr/bin/eval_file # or other directory that is in $PATH
+hash -r # run this just in case to refresh $PATH in your terminal
+
+eval_file file.b # 1st argument is the name of the file
+```