golangci-lint configuration file

golangci-lint can run all the currently enabled linters, and as far as I
can tell, does it in under 5 seconds as opposed to over 180 seconds
(compare `time make cilint` and `time make lint`).

Some of the linters that are listed in the "enabled" section but
commented out looked like a good idea to me, and fairly low hanging
fruit to fix, but they are not passing at the moment.

All the linters covered in the current Makefile are run.

TODO:
- replace lint target in Makefile with golangci-lint
- remove .github/workflow/errcheck.yml

modules/resourceusage/widget.go

@@ -121,7 +121,7 @@ func MakeGraph(widget *Widget) {
 		}
 	}
 
-	widget.BarGraph.BuildBars(stats[:])
+	widget.BarGraph.BuildBars(stats)
 
 }