build: add package comments to silence revive linter

vfs/vfs.go

@@ -10,15 +10,14 @@
 // may be referred to as "".  However Stat strips slashes so you can
 // use paths with slashes in.
 //
-// It also includes directory caching
+// # It also includes directory caching
 //
 // The vfs package returns Error values to signal precisely which
 // error conditions have ocurred.  It may also return general errors
 // it receives.  It tries to use os Error values (e.g. os.ErrExist)
 // where possible.
-
+//
 //go:generate sh -c "go run make_open_tests.go | gofmt > open_test.go"
-
 package vfs
 
 import (

vfs/vfscache/downloaders/downloaders.go

@@ -1,3 +1,4 @@
+// Package downloaders provides utilities for the VFS layer
 package downloaders
 
 import (

vfs/vfscommon/cachemode.go

@@ -1,3 +1,4 @@
+// Package vfscommon provides utilities for VFS.
 package vfscommon
 
 import (

vfs/vfstest/vfs.go

@@ -1,3 +1,4 @@
+// Package vfstest provides tests for VFS.
 package vfstest
 
 import (