feat(challenge11): add readme to challenge 11

apps/rxjs-pipe-bug/README.md

@@ -1,18 +1,26 @@
-<h1>Rxjs pipe bug</h1>
+<h1>BUG: RxJs chaining operators</h1>
 
 > Author: Thomas Laforge
 
-<!-- TODO: add Information/Statement/Rules/Constraint/Steps -->
+Let's dive inside the wonderful word of RxJs.
 
-### Information
+This challenge is inspired by a real-life example.
 
-### Statement
+### Presentation of the challenge
 
-### Step 1
+#### User Story
 
-### Step 2
+We need a button for each `Topic`. When we click on it, we delete all objects with this `Topic` in our database _(Fake DB in our case)_. Finally we display **All [topic] have been deleted** is everything was deleted successfully or **Error: deletion of some [topic] failed** if some deletions failed
 
-### Constraints:
+#### Constraints:
+
+We can only pass one object to our DB for deletion at the time. The DB will respond true if the data was successfully deleted and false otherwise.
+
+### What you need to do
+
+The QA team reports a **bug**. The UI shows **All [topic] have been deleted** all the time, even if some deletions fail.
+
+👉 Spot the bug and correct it.
 
 ### Submitting your work
 
@@ -24,8 +32,6 @@
 6. Commit your work
 7. Submit a PR with a title beginning with **Answer:11** that I will review and other dev can review.
 
-<!-- TODO: add challenge number and project Name -->
-
 <a href="https://github.com/tomalaforge/angular-challenges/pulls?q=label%3A11+label%3Aanswer"><img src="https://img.shields.io/badge/-Solutions-green" alt="Rxjs pipe bug"/></a>
 
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