Update a ton of things

part6/README.md

@@ -4,16 +4,16 @@ Part 6
 ## Installation
 
 ```bash
-elm package install
+elm-package install
 ```
 
 (Answer `y` at the prompt. In rare cases a known issue can cause the download
-to fail; in that case, just run `elm package install` again.)
+to fail; in that case, just run `elm-package install` again.)
 
 ## Building
 
 ```bash
-elm live Main.elm --open -- --output=elm.js
+elm-live Main.elm --open -- --output=elm.js
 ```
 
 ## References