Update files.am: add notes on

See #818 (comment)

modules/files.am

@@ -139,6 +139,18 @@ _files_show_only_number() {
 	exit 0
 }
 
+_files_appimage_type_notes() {
+	if grep -q "appimage" "$AMCACHEDIR"/files*; then
+		if grep -q "appimage2" "$AMCACHEDIR"/files*; then
+			printf " *appimage2 needs libfuse2 and fusermount installed\n"
+		fi
+		if grep -q "appimage3" "$AMCACHEDIR"/files*; then
+			printf " *appimage3 does not need libfuse but needs fusermount3 or higher\n"
+		fi
+		printf "\n"
+	fi
+}
+
 _files_total_size() {
 	if [ "$(_files_show_only_number)" = "0" ]; then
 		printf "\n TOTAL SIZE: $(du -ch $(find -type d -name 'modules' -printf "%h\n") 2>/dev/null | awk 'END {print $1"iB"}' | sed 's/...$/ &/') of disk space in use\n\n"
@@ -157,6 +169,7 @@ _files_sort_by_name() {
 	sort "$AMCACHEDIR"/files-args 2>/dev/null >> "$AMCACHEDIR"/files-args-byname
 	column -t "$AMCACHEDIR"/files-args-byname
 	_files_total_size
+	_files_appimage_type_notes
 }
 
 _files_sort_by_size() {
@@ -168,6 +181,7 @@ _files_sort_by_size() {
 	cat "$AMCACHEDIR"/files-args >> "$AMCACHEDIR"/files-args-bysize 2>/dev/null
 	column -t "$AMCACHEDIR"/files-args-bysize
 	_files_total_size
+	_files_appimage_type_notes
 }
 
 if [ "$2" = "--less" ]; then