add 0 and G motions

shlide

···
 
     slides_dir="${1:-./}"
     slides=("$slides_dir"/[0-9]*.txt)
+    total="${#slides[@]}"
     i=0
-    while true; do
+    while :; do
         # Clear the screen.
         printf '\e[2J'
 
···
         trap 'die' INT
 
         # Display END reached prompt, and then exit.
-        [[ "$i" -eq "${#slides[@]}" ]] && {
+        [[ "$i" -eq "$total" ]] && {
             display_end
             read -rsn1 input
             case "$input" in
···
                     die
                     ;;
                 *)
-                    ((--i))
+                    ((i=0))
                     ;;
             esac
         }
···
         [[ "$i" -lt 0 ]] && i=0
 
         # Navigate on j/k/n/p and quit on q.
-        display "$(<"${slides[$i]}")" "${slides[$i]}" "$i" "${#slides[@]}"
+        display "$(<"${slides[$i]}")" "${slides[$i]}" "$i" "$total"
         read -rsn1 input
         case "$input" in 
             "j"|"n"|"")
···
                 ;;
             "k"|"p")
                 ((--i))
+                ;;
+            "0")
+                ((i=0))
+                ;;
+            "G")
+                ((i=total-1))
                 ;;
             "q")
                 # Return the cursor on exit.