docs: say that support for Git's remote config is partial

#4889

docs/git-compatibility.md

@@ -18,7 +18,10 @@ a comparison with Git, including how workflows are different, see the
 * **Configuration: Partial.** The only configuration from Git (e.g. in
   `~/.gitconfig`) that's respected is the following. Feel free to file a bug if
   you miss any particular configuration options.
-  * The configuration of remotes (`[remote "<name>"]`).
+  * The configuration of remotes (`[remote "<name>"]`). Only the names and URLs
+    are respected (refspecs are not respected, and
+    [only the last pushurl](https://github.com/martinvonz/jj/issues/4889) is
+    respected).
   * `core.excludesFile`
 * **Authentication: Partial.** Only `ssh-agent`, a password-less key (
   only `~/.ssh/id_rsa`, `~/.ssh/id_ed25519` or `~/.ssh/id_ed25519_sk`), or