Add "help" command (#3)

histd.sh

@@ -42,6 +42,16 @@ function merge {
     find $BASE_DIR -type f -name "*.md" -exec echo "# {}" \; -exec cat "{}" \; -exec echo \;
 }
 
+function help {
+    echo "Histd - How I Spent This Day"
+    echo "A simple personal diary app"
+    echo
+    echo "Usage:"
+    echo "- histd.sh - open a text editor to describe the current day"
+    echo "- histd.sh backup - create an archive of all notes"
+    echo "- histd.sh merge - print all notes"
+    echo "- histd.sh help - show this message"
+}
 
 # Prepare the environment
 BASE_DIR=~/.local/share/histd
@@ -54,6 +64,10 @@ elif [[ $1 == "backup" ]]; then
     backup
 elif [[ $1 == "merge" ]]; then
     merge
+elif [[ $1 == "help" ]]; then
+    help
 else
     echo Command not found
+    echo
+    help
 fi