Fix and clarify block wrap preferences (DistributedProofreaders#512)

1. Add `/#` to tooltip for blockquote settings
2. Add `Nowrap` to label for block settings
3. Remove `/P` from tooltip for block settings

src/guiguts/misc_dialogs.py

@@ -171,19 +171,19 @@ def add_label_spinbox(row: int, label: str, key: PrefKey, tooltip: str) -> None:
             2,
             "Blockquote Indent:",
             PrefKey.WRAP_BLOCKQUOTE_INDENT,
-            "Extra indent for each level of blockquotes",
+            "Extra indent for each level of /# blockquotes",
         )
         add_label_spinbox(
             3,
             "Blockquote Right Margin:",
             PrefKey.WRAP_BLOCKQUOTE_RIGHT_MARGIN,
-            "Right margin for blockquotes",
+            "Right margin for /# blockquotes",
         )
         add_label_spinbox(
             4,
-            "Block Indent:",
+            "Nowrap Block Indent:",
             PrefKey.WRAP_BLOCK_INDENT,
-            "Indent for /*, /P, /L blocks",
+            "Indent for /* and /L blocks",
         )
         add_label_spinbox(
             5,