doc: fixed typo in graph

doc/acceptance.md

@@ -12,7 +12,7 @@ The Acceptance process slightly differs whether you are a project's *developer*
 
 ```mermaid
 stateDiagram
-    Submitted: CR Submitted
+    Submitted: MR Submitted
     InReview: In Review
     [*] --> Submitted: A VLC developer submitted
     Submitted --> Rejected: NOT mergeable by gitlab
@@ -33,7 +33,7 @@ stateDiagram
 
 ```mermaid
 stateDiagram
-    Submitted: CR Submitted
+    Submitted: MR Submitted
     InReview: In Review
     [*] --> Submitted: A VLC developer submitted
     Submitted --> Rejected: NOT mergeable by gitlab