Fix typo ("Go tool" -> "Go tools")

README.md

@@ -46,7 +46,7 @@ Put your actual application code in the `/internal/app` directory (e.g., `/inter
 
 Library code that's ok to use by external applications (e.g., `/pkg/mypubliclib`). Other projects will import these libraries expecting them to work, so think twice before you put something here :-)
 
-It's also a way to group Go code in one place when your root directory contains lots of non-Go components and directories making it easier to run various Go tool (as mentioned in the [`Best Practices for Industrial Programming`](https://www.youtube.com/watch?v=PTE4VJIdHPg) from GopherCon EU 2018).
+It's also a way to group Go code in one place when your root directory contains lots of non-Go components and directories making it easier to run various Go tools (as mentioned in the [`Best Practices for Industrial Programming`](https://www.youtube.com/watch?v=PTE4VJIdHPg) from GopherCon EU 2018).
 
 See the [`/pkg`](pkg/README.md) directory if you want to see which popular Go repos use this project layout pattern. This is a common layout pattern, but it's not universally accepted and some in the Go community don't recommend it.