Added comment to explain weird use of associative array syntax

build.sh

@@ -108,7 +108,8 @@ add_header_and_footer() {
 	cp "$BASE_PATH/header.html" "$BASE_PATH/temp/$parent_dir/temp_header.html"
 
 #	Check for relevant metadata, and perform corresponding action
-	if [[ ! -v "meta_array["date"]" ]]; then # If there is no date
+	# This syntax is intended (although it doesn't follow typical Bash array syntax). See https://stackoverflow.com/a/45385463 for more info.
+	if [[ ! -v "meta_array[date]" ]]; then # If there is no date
 		sed -i '$ d' "$BASE_PATH/temp/$parent_dir/temp_header.html" # remove the 'date published' section of the header
 	fi