describe workaround to local variable confusion

SC2178.md

@@ -39,3 +39,34 @@ Another possible cause is accidentally missing the `$` on a previous assignment:
 ### Exceptions:
 
 ShellCheck can get confused by variable scope if the same variable name was used as an array previously, but is a string in the current context. You can [[ignore]] it in this case.
+
+In the case of local variables, a workaround is to declare the local variable separately from assigning to it:
+
+**Problematic Code:**
+```sh
+foo () {
+   local -a baz
+   baz+=("foo" "bar")
+   echo "${baz[@]}"
+}
+
+bar () {
+   local baz="qux"
+   echo "$baz"
+}
+```
+
+**Correct Code:**
+```sh
+foo () {
+   local -a baz
+   baz+=("foo" "bar")
+   echo "${baz[@]}"
+}
+
+bar () {
+   local baz
+   baz="qux"
+   echo "$baz"
+}
+```