docs: fix markdown lint issues in command docs

cmd/test/histogram/histogram.go

@@ -26,8 +26,7 @@ var commandDefinition = &cobra.Command{
 in filenames in the remote:path specified.
 
 The data doesn't contain any identifying information but is useful for
-the rclone developers when developing filename compression.
-`,
+the rclone developers when developing filename compression.`,
 	Annotations: map[string]string{
 		"versionIntroduced": "v1.55",
 	},

cmd/test/info/info.go

@@ -68,8 +68,7 @@ paths passed in and how long they can be.  It can take some time.  It will
 write test files into the remote:path passed in.  It outputs a bit of go
 code for each one.
 
-**NB** this can create undeletable files and other hazards - use with care
-`,
+**NB** this can create undeletable files and other hazards - use with care!`,
 	Annotations: map[string]string{
 		"versionIntroduced": "v1.55",
 	},

cmd/test/test.go

@@ -18,13 +18,14 @@ var Command = &cobra.Command{
 
 Select which test command you want with the subcommand, eg
 
-    rclone test memory remote:
+` + "```sh" + `
+rclone test memory remote:
+` + "```" + `
 
 Each subcommand has its own options which you can see in their help.
 
 **NB** Be careful running these commands, they may do strange things
-so reading their documentation first is recommended.
-`,
+so reading their documentation first is recommended.`,
 	Annotations: map[string]string{
 		"versionIntroduced": "v1.55",
 	},