docs: refer to "squash" in help screen for git node land

Signed-off-by: Stewart X Addison <sxa@ibm.com>

Author: sxa

components/git/land.js

@@ -48,8 +48,8 @@ const landActions = {
     type: 'boolean'
   },
   fixupAll: {
-    describe: 'Automatically fixup all commits to the first one dismissing ' +
-      'other commit messages',
+    describe: 'Automatically fixup (squash) all commits to the first one ' +
+      'dismissing other commit messages',
     default: false,
     type: 'boolean'
   },