Add more examples useage for the output flag

As it wasn't mentioning the html output before

Author: razzeee

ui/terminal/src/Main.hs

@@ -197,7 +197,7 @@ make =
       flags Make.Flags
         |-- onOff "debug" "Turn on the time-travelling debugger. It allows you to rewind and replay events. The events can be imported/exported into a file, which makes for very precise bug reports!"
         |-- onOff "optimize" "Turn on optimizations to make code smaller and faster. For example, the compiler renames record fields to be as short as possible and unboxes values to reduce allocation."
-        |-- flag "output" Output.output "Specify the name of the resulting JS file. For example --output=assets/elm.js to generate the JS at assets/elm.js or --output=/dev/null to generate no output at all!"
+        |-- flag "output" Output.output "Specify the name of the resulting JS or Html file. For example --output=assets/elm.js to generate the JS at assets/elm.js, --output=assets/index.html to generate a Html file or --output=/dev/null to generate no output at all!"
         |-- flag "report" Make.reportType "You can say --report=json to get error messages as JSON. This is only really useful if you are an editor plugin. Humans should avoid it!"
         |-- flag "docs" Make.docsFile "Generate a JSON file of documentation for a package. Eventually it will be possible to preview docs with `reactor` because it is quite hard to deal with these JSON files directly."
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