add bash completion

builder/data/etc/bash_completion.d/pwnagotchi_completion.sh

@@ -0,0 +1,17 @@
+_show_complete()
+{
+    local cur prev opts node_names
+    COMPREPLY=()
+    cur="${COMP_WORDS[COMP_CWORD]}"
+    cmd="${COMP_WORDS[@]:0:${#COMP_WORDS[@]}-1}"
+    if [[ ${cur} == -* ]] ; then
+        opts="$($cmd --help | tr ' ' '\n' | awk '/^ *-/{gsub("[^a-zA-Z0-9-]","",$1);print $1}')"
+        COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+        return 0
+    fi
+
+    opts="$($cmd --help | sed -n '/positional arguments:/ {n;p}' | tr ',' '\n' | awk '{gsub("[^a-zA-Z0-9-]", "", $1); print $1}')"
+    COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+}
+
+complete -F _show_complete pwnagotchi