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/tac.go

@@ -0,0 +1,19 @@
+package sys
+
+import (
+	"github.com/versenilvis/iris/commands/core"
+)
+
+func init() {
+	core.Register(&core.Spec{
+		Name:        "tac",
+		Description: "Concatenate and print files in reverse",
+		Options: []core.Option{
+			{Name: "--help", Description: "Display this help and exit"},
+			{Name: "--before", Description: "Attach the separator before instead of after"},
+			{Name: "--regex", Description: "Interpret the separator as a regular expression"},
+			{Name: "--separator", Description: "Use STRING as the separator instead of newline"},
+			{Name: "--version", Description: "Output version information and exit"},
+		},
+	})
+}