EX templates: Use GH sub-issues (#3036)

Author: manuroe

.github/ISSUE_TEMPLATE/ex-prep.yml

@@ -23,20 +23,21 @@ body:
       - 
       
       # Subtasks
-      ```[tasklist]
+      Subtasks should be created as separate GitHub issues in the corresponding platform repositories.
+      Add them as sub-issues of this prep task.  
+      (Optional) You may also list them below as checklist items for quick visibility.
+  
       ### Android
-      ```
+      -
 
-      ```[tasklist]
       ### iOS
-      ```
-
-      ```[tasklist]
-      ### Rust
-      ```
+      -
 
-      ```[tasklist]
+      ### Rust
+      -
+   
       ### Other
-      ```
+      -
+  
   validations:
     required: false

.github/ISSUE_TEMPLATE/ex-story-standalone.yml

@@ -12,30 +12,33 @@ body:
       * I want to [objective]
       * So that [value generated]
 
-      ### Acceptance criteria
+      # Acceptance criteria
       - TBD
 
-      ### Leads
+      # Leads
       * Tech: <GitHub id>
       * Design: <GitHub id>
 
       ### Time sheeting
       <!--The project to report the time spent on the feature-->
       ?
 
-      ### Documentation
+      # Documentation
       - 
 
-      ### Dependencies
+      # Dependencies
       - None
 
-      ### Out of scope
+      # Out of scope
       - Nothing
 
-      ### Open questions
-      - [ ] 
+      # Open questions
+      - [x] None
 
-      ## Subtasks
+      # Subtasks
+      Subtasks should be created as separate GitHub issues in the corresponding platform repositories.
+      Add them as sub-issues of this user story.
+      (Optional) You may also list them below as checklist items for quick visibility.
 
       ### Android
       -
@@ -50,12 +53,5 @@ body:
       -
 
       ## Sign-offs
-      ### Android
-      - [ ] Design sign-off on completion
-      - [ ] QA sign-off on completion
-      - [ ] Product sign-off on completion
-
-      ### iOS
-      - [ ] Design sign-off on completion
-      - [ ] QA sign-off on completion
-      - [ ] Product sign-off on completion
+      - [ ] Android
+      - [ ] iOS

.github/ISSUE_TEMPLATE/ex-story.yml

@@ -12,19 +12,22 @@ body:
       * I want to [objective]
       * So that [value generated]
 
-      ### Acceptance criteria
+      # Acceptance criteria
       - TBD
 
-      ### Dependencies
+      # Dependencies
       - None
 
-      ### Out of scope
+      # Out of scope
       - Nothing
 
-      ### Questions
-      - [ ] 
+      # Questions
+      - [x] None
 
-      ## Subtasks
+      # Subtasks
+      Subtasks should be created as separate GitHub issues in the corresponding platform repositories.
+      Add them as sub-issues of this user story.
+      (Optional) You may also list them below as checklist items for quick visibility.
 
       ### Android
       -