Use pathability groups (thanks @myk002) to detect stranded citizens

docs/warn-stranded.rst

@@ -2,18 +2,18 @@ warn-stranded
 =============
 
 .. dfhack-tool::
-    :summary: Reports citizens that are stranded and can't reach any other unit.
+    :summary: Reports citizens that are stranded and can't reach any other citizens.
     :tags: fort units
 
-If any (live) groups of units are stranded from the main (largest) group,
-the game will pause and you'll get a warning dialog telling you which units are isolated.
+If any (live) groups of fort citizens are stranded from the main (largest) group,
+the game will pause and you'll get a warning dialog telling you which citizens are isolated.
 This gives you a chance to rescue them before they get overly stressed or start starving.
 
-Each unit will be put into a group with the other units stranded together.
+Each ciitizen will be put into a group with the other citizens stranded together.
 
-There is a command line interface that can print status of units without pausing or bringing up a window.
+There is a command line interface that can print status of citizens without pausing or bringing up a window.
 
-The GUI and command-line both also have the ability to ignore units so they don't trigger a pause and window.
+The GUI and command-line both also have the ability to ignore citizens so they don't trigger a pause and window.
 
 You can enable ``warn-stranded`` notifications in `gui/control-panel` on the "Maintenance" tab.
 
@@ -30,20 +30,24 @@ Usage
 Examples
 --------
 
+``warn-stranded``
+    Standard command that checks for standed citizens and causes a window to pop up with a warning if any are stranded.
+    Does nothing when there are no unignored stranded citizens.
+
 ``warn-stranded status``
-    List all stranded units and all ignored units. Includes unit ids in the output.
+    List all stranded citizens and all ignored citizens. Includes citizen unit ids.
 
 ``warn-stranded clear``
-    Clear(unignore) all ignored units.
+    Clear(unignore) all ignored citizens.
 
 ``warn-stranded ignore 1``
-    Ignore unit with id 1.
+    Ignore citizen with unit id 1.
 
 ``warn-stranded ignoregroup 2``
-    Ignore stranded unit group 2.
+    Ignore stranded citizen group 2.
 
 ``warn-stranded unignore  1``
-    Unignore unit with id 1.
+    Unignore citizen with unit id 1.
 
 ``warn-stranded unignoregroup 3``
-    Unignore stranded unit group 3.
+    Unignore stranded citizen group 3.