use uppercase letters for flag usage

Signed-off-by: panguicai008 <guicai.pan@daocloud.io>

cmd/ctr/commands/images/convert.go

@@ -30,7 +30,7 @@ import (
 
 var convertCommand = cli.Command{
 	Name:      "convert",
-	Usage:     "convert an image",
+	Usage:     "Convert an image",
 	ArgsUsage: "[flags] <source_ref> <target_ref>",
 	Description: `Convert an image format.
 

cmd/ctr/commands/images/export.go

@@ -35,7 +35,7 @@ import (
 
 var exportCommand = cli.Command{
 	Name:      "export",
-	Usage:     "export images",
+	Usage:     "Export images",
 	ArgsUsage: "[flags] <out> <image> ...",
 	Description: `Export images to an OCI tar archive.
 
@@ -64,7 +64,7 @@ When '--all-platforms' is given all images in a manifest list must be available.
 		},
 		cli.BoolTFlag{
 			Name:  "local",
-			Usage: "run export locally rather than through transfer API",
+			Usage: "Run export locally rather than through transfer API",
 		},
 	},
 	Action: func(context *cli.Context) error {

cmd/ctr/commands/images/images.go

@@ -37,7 +37,7 @@ import (
 var Command = cli.Command{
 	Name:    "images",
 	Aliases: []string{"image", "i"},
-	Usage:   "manage images",
+	Usage:   "Manage images",
 	Subcommands: cli.Commands{
 		checkCommand,
 		exportCommand,
@@ -59,7 +59,7 @@ var Command = cli.Command{
 var listCommand = cli.Command{
 	Name:        "list",
 	Aliases:     []string{"ls"},
-	Usage:       "list images known to containerd",
+	Usage:       "List images known to containerd",
 	ArgsUsage:   "[flags] [<filter>, ...]",
 	Description: "list images registered with containerd",
 	Flags: []cli.Flag{
@@ -142,7 +142,7 @@ var listCommand = cli.Command{
 
 var setLabelsCommand = cli.Command{
 	Name:        "label",
-	Usage:       "set and clear labels for an image",
+	Usage:       "Set and clear labels for an image",
 	ArgsUsage:   "[flags] <name> [<key>=<value>, ...]",
 	Description: "set and clear labels for an image",
 	Flags: []cli.Flag{
@@ -201,7 +201,7 @@ var setLabelsCommand = cli.Command{
 
 var checkCommand = cli.Command{
 	Name:        "check",
-	Usage:       "check existing images to ensure all content is available locally",
+	Usage:       "Check existing images to ensure all content is available locally",
 	ArgsUsage:   "[flags] [<filter>, ...]",
 	Description: "check existing images to ensure all content is available locally",
 	Flags: append([]cli.Flag{
@@ -315,7 +315,7 @@ var checkCommand = cli.Command{
 var removeCommand = cli.Command{
 	Name:        "delete",
 	Aliases:     []string{"del", "remove", "rm"},
-	Usage:       "remove one or more images by reference",
+	Usage:       "Remove one or more images by reference",
 	ArgsUsage:   "[flags] <ref> [<ref>, ...]",
 	Description: "remove one or more images by reference",
 	Flags: []cli.Flag{

cmd/ctr/commands/images/import.go

@@ -37,7 +37,7 @@ import (
 
 var importCommand = cli.Command{
 	Name:      "import",
-	Usage:     "import images",
+	Usage:     "Import images",
 	ArgsUsage: "[flags] <in>",
 	Description: `Import images from a tar stream.
 Implemented formats:

cmd/ctr/commands/images/mount.go

@@ -32,7 +32,7 @@ import (
 
 var mountCommand = cli.Command{
 	Name:      "mount",
-	Usage:     "mount an image to a target path",
+	Usage:     "Mount an image to a target path",
 	ArgsUsage: "[flags] <ref> <target>",
 	Description: `Mount an image rootfs to a specified path.
 

cmd/ctr/commands/images/pull.go

@@ -41,7 +41,7 @@ import (
 
 var pullCommand = cli.Command{
 	Name:      "pull",
-	Usage:     "pull an image from a remote",
+	Usage:     "Pull an image from a remote",
 	ArgsUsage: "[flags] <ref>",
 	Description: `Fetch and prepare an image for use in containerd.
 

cmd/ctr/commands/images/push.go

@@ -46,7 +46,7 @@ import (
 
 var pushCommand = cli.Command{
 	Name:      "push",
-	Usage:     "push an image to a remote",
+	Usage:     "Push an image to a remote",
 	ArgsUsage: "[flags] <remote> [<local>]",
 	Description: `Pushes an image reference from containerd.
 

cmd/ctr/commands/images/tag.go

@@ -28,7 +28,7 @@ import (
 
 var tagCommand = cli.Command{
 	Name:        "tag",
-	Usage:       "tag an image",
+	Usage:       "Tag an image",
 	ArgsUsage:   "[flags] <source_ref> <target_ref> [<target_ref>, ...]",
 	Description: `Tag an image for use in containerd.`,
 	Flags: []cli.Flag{
@@ -38,7 +38,7 @@ var tagCommand = cli.Command{
 		},
 		cli.BoolTFlag{
 			Name:  "local",
-			Usage: "run tag locally rather than through transfer API",
+			Usage: "Run tag locally rather than through transfer API",
 		},
 	},
 	Action: func(context *cli.Context) error {

cmd/ctr/commands/images/unmount.go

@@ -28,7 +28,7 @@ import (
 
 var unmountCommand = cli.Command{
 	Name:        "unmount",
-	Usage:       "unmount the image from the target",
+	Usage:       "Unmount the image from the target",
 	ArgsUsage:   "[flags] <target>",
 	Description: "Unmount the image rootfs from the specified target.",
 	Flags: append(append(commands.RegistryFlags, append(commands.SnapshotterFlags, commands.LabelFlag)...),