Add Symfony 3 special case on depends command doc

doc/03-cli.md

@@ -341,13 +341,20 @@ symfony/monolog-bridge requires monolog/monolog (>=1.2)
 symfony/symfony requires monolog/monolog (~1)
 ```
 
+If you want, for example, find any package that is **not** ready
+for Symfony 3 or one of its components, you can run the following command:
+
+```sh
+php composer.phar depends symfony/symfony --with-replaces -im ^3.0
+```
+
 ### Options
 
 * **--link-type:** The link types to match on, can be specified multiple
   times.
 * **--match-constraint (-m):** Filters the dependencies shown using this constraint.
 * **--invert-match-constraint (-i):** Turns --match-constraint around into a blacklist
-  insteead of a whitelist.
+  instead of a whitelist.
 * **--with-replaces:** Search for replaced packages as well.
 
 ## validate