add "-D" for --rst_on_stdin

Author: gpshead

src/blurb/blurb.py

@@ -909,7 +909,7 @@ def _find_smart_matches(section):
 @app.command(name="add")
 def add(*, issue: Annotated[Optional[str], Parameter(alias=["-i"])] = None,
         section: Annotated[Optional[str], Parameter(alias=["-s"])] = None,
-        rst_on_stdin: bool = False):
+        rst_on_stdin: Annotated[bool, Parameter(alias=["-D"])] = False):
     # This docstring template is formatted after the function definition.
     """Add a new Misc/NEWS entry (default command).