Fix vscode config to watch file changes

Fix the documentation by using the correct configuration for
watching file changes outside of the editor.

Fixes https://github.com/microsoft/vscode-go/issues/2810

Change-Id: Ib550d9831fe4563ceb5917d9196b201a03b051d2
GitHub-Last-Rev: 86c49abed8a0c79b641e02a23128b4654d2d6d48
GitHub-Pull-Request: golang/tools#169
Reviewed-on: https://go-review.googlesource.com/c/tools/+/199578
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/gopls/doc/vscode.md b/gopls/doc/vscode.md
index dd2be6a..0c95aa6 100644
--- a/gopls/doc/vscode.md
+++ b/gopls/doc/vscode.md
@@ -16,7 +16,7 @@
 
     // Experimental settings
     "completeUnimported": true, // autocomplete unimported packages
-    "watchChangedFiles": true,  // watch file changes outside of the editor
+    "watchFileChanges": true,  // watch file changes outside of the editor
     "deepCompletion": true,     // enable deep completion
 },
 "files.eol": "\n", // formatting only supports LF line endings