Adding analyzer feedback for tim-from-marketing concept exercise (#2754)

* Adding analyzer feedback for tim-from-marketing concept exercise

* Adding another actionable comment when students use optionals

* Update exercises/concept/tim-from-marketing/.meta/design.md

Co-authored-by: Sander Ploegsma <sanderploegsma@gmail.com>

* Removing essential comment

---------

Co-authored-by: Sander Ploegsma <sanderploegsma@gmail.com>

Author: manumafe98

exercises/concept/tim-from-marketing/.meta/design.md

@@ -18,3 +18,16 @@
 
 - `strings`: strings will be compared to null and basic methods from strings will be called.
 - `if-else-statements`: using a conditional statement.
+
+## Analyzer
+
+This exercise could benefit from the following rules in the [analyzer]:
+
+- `actionable`: If the solution uses `Optionals` to solve the exercise, encourage the student to try solving it using `null` instead.
+- `informative`: If the solution uses `String.format`, instruct the student to use simple string concatenation instead.
+  Explain that `String.format` is significantly slower than concatenating strings and should be used in more complex scenarios.
+
+If the solution does not receive any of the above feedback, it must be exemplar.
+Leave a `celebratory` comment to celebrate the success!
+
+[analyzer]: https://github.com/exercism/java-analyzer