Fix conan search command

--all is not accepted here (tested with conan 1.33.1)

doc/user/packages/conan_repository/index.md

@@ -128,7 +128,7 @@ To add the remote:
    For example:
 
    ```shell
-   conan search Hello* --all --remote=gitlab
+   conan search Hello* --remote=gitlab
    ```
 
 ### Add a remote for your instance