[README] Minor improvements.

README.md

@@ -108,14 +108,14 @@ targets, thus you can install **lua-osx** system wide by running:
 
 **lua-osx** uses [LDoc](https://github.com/lunarmodules/LDoc) for documentation.
 
-You can generate documentation using `ldoc` directly, with the following command:
+You can generate documentation using `ldoc` directly, running the following command:
 ```sh
-ldoc .
+$ ldoc .
 ```
 
 Or using the `doc` `Makefile` target:
 ```sh
-make doc
+$ make doc
 ```
 
 Both methods generate a `doc` directory, open `doc/index.html`