ci: add autocompletion and manpage

cli/scripts/completions.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+set -e
+rm -rf completions
+mkdir completions
+cd cli
+for sh in bash zsh fish; do
+	go run . completion "$sh" > "../completions/infisical.$sh"
+done

cli/scripts/manpages.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+set -e
+rm -rf manpages
+mkdir manpages
+cd cli
+go run . man | gzip -c > "../manpages/infisical.1.gz"