feat(commands): more commands (#30)

- I wrote a scripts to copy and generate all commands missing in iris
from fig repo: https://github.com/withfig/autocomplete
- Add a new script to generate commands docs about which commands
currently are inside commands folder
377d4aac663590e504fe39a92eb4dac4cbd333b2
- Add more icons e64d4e70a1db61e62053460a882e093bd6373ab1

commands/sys/crontab.go

@@ -0,0 +1,18 @@
+package sys
+
+import (
+	"github.com/versenilvis/iris/commands/core"
+)
+
+func init() {
+	core.Register(&core.Spec{
+		Name:        "crontab",
+		Description: "Maintain crontab file for individual users",
+		Options: []core.Option{
+			{Name: "-e", Description: "Edit the current crontab"},
+			{Name: "-l", Description: "Display the current crontab"},
+			{Name: "-r", Description: "Remove the current crontab"},
+			{Name: "-u", Description: "Specify the name of the user whose crontab is to be tweaked"},
+		},
+	})
+}