watchman: update main page (#16489)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

pages/common/watchman.md

@@ -3,9 +3,9 @@
 > A service that watches files, and triggers actions when changes occur.
 > More information: <https://facebook.github.io/watchman/docs/cli-options>.
 
-- Start watching a directory for changes:
+- Infer the root directory of the project containing the specified directory, and watch its files and sub-folders for changes:
 
-`watchman watch {{path/to/directory}}`
+`watchman watch-project {{path/to/directory}}`
 
 - Add a trigger to run a command when files with a specified filename pattern in a watched directory change:
 
@@ -15,10 +15,14 @@
 
 `watchman watch-list`
 
-- Delete a watch on a directory:
+- Delete a watch on a directory and its associated triggers:
 
 `watchman watch-del {{path/to/watched_directory}}`
 
+- Delete all watched directories and triggers:
+
+`watchman watch-del-all`
+
 - List all triggers on a watched directory:
 
 `watchman trigger-list {{path/to/watched_directory}}`
@@ -26,3 +30,7 @@
 - Delete a trigger from a watched directory:
 
 `watchman trigger-del {{path/to/watched_directory}} {{trigger_name}}`
+
+- Temporarily stop `watchman`, until the next time you call a `watchman` command:
+
+`watchman shutdown-server`