mw/errors: doc
Remove the [FILE] option from the docs, we still allow it, but this one
value that we allow now *stdout* isn't shown anymore.
Also test the snippet with readme_test.go by adding `~~ corefile`.
*errors* enables error logging.
-Any errors encountered during the query processing will be printed on standard output.
+Any errors encountered during the query processing will be printed to standard output.
## Syntax
~~~
-errors [FILE]
+errors
~~~
-* **FILE** is the log file to create (or append to). The *only* valid name for **FILE** is *stdout*
-
## Examples
-Log errors to *stdout*.
+Use the *whoami* to respond to queries and Log errors to standard output.
-~~~
+~~~ corefile
+. {
+ whoami
errors
-~~~
-
-Log errors to *stdout*.
-
-~~~
-errors stdout
+}
~~~
