Change the wording in diagnostic.yaml to reduce confusion

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

.github/ISSUE_TEMPLATE/diagnostics.yaml

@@ -1,13 +1,15 @@
 name: Diagnostic issue
-description: Create a bug report or feature request for a change to `rustc`'s error output
+description: Create a report for a change to `rustc`'s error output
 labels: ["A-diagnostics", "T-compiler"]
 body:
   - type: markdown
     attributes:
       value: |
-        Thank you for filing a diagnostics bug report! 🐛
+        Thank you for filing a diagnostics report! 🐛
 
-        Please provide a short summary of the bug, along with any information you feel relevant to replicating the bug.
+        You can report a bug or a feature request for a change to `rustc`'s error output.
+
+        Please provide a short summary of the issue, along with any information you feel relevant to replicating the issue.
 
         If you cannot produce a minimal reproduction case (something that would work in isolation), please provide the steps or even link to a repository that causes the problematic output to occur.
   - type: textarea