Clean up E0715 explanation

GuillaumeGomez · GuillaumeGomez · commit 13a6aeff7706 · 2020-07-01T14:13:41.000+02:00
diff --git a/src/librustc_error_codes/error_codes/E0715.md b/src/librustc_error_codes/error_codes/E0715.md
@@ -15,8 +15,7 @@ struct OverrideConst;
 impl Marker for OverrideConst { // error!
     const N: usize = 1;
 }
-
-fn main() {}
+# fn main() {}
 ```
 
 Because marker traits are allowed to have multiple implementations for the same

Original file line number	Diff line number	Diff line change
`@@ -15,8 +15,7 @@ struct OverrideConst;`
`15`	`15`	`impl Marker for OverrideConst { // error!`
`16`	`16`	`const N: usize = 1;`
`17`	`17`	`}`
`18`		`-`
`19`		`-fn main() {}`
	`18`	`+# fn main() {}`
`20`	`19`	```
`21`	`20`
`22`	`21`	`Because marker traits are allowed to have multiple implementations for the same`