Updated SC2124 (markdown)

SC2124.md

@@ -50,3 +50,13 @@ The same is true for `${@: -1}`, which results in 0 or 1 elements: `var=${*: -1}
 ### Exceptions
 
 None.
+
+### Adding an element to an array may trigger this warning when you forget the parenthesis.
+```
+filelist="${filelist[@]}" "$filename"
+```
+What was meant is:
+```
+filelist=("${filelist[@]}" "$filename")
+```
+Note: this syntax is compatible with older shells, in later shells (bash 3.1+ and zsh 4.2+) you can do: ```filelist+=("$filename")```