completions/git: show url as description for remote completion

CHANGELOG.rst

@@ -62,6 +62,7 @@ New or improved bindings
 
 Completions
 ^^^^^^^^^^^
+- ``git`` completions now show the remote url as a description when completing remotes.
 
 Improved terminal support
 ^^^^^^^^^^^^^^^^^^^^^^^^^

share/completions/git.fish

@@ -96,7 +96,9 @@ function __fish_git_refs
 end
 
 function __fish_git_remotes
-    __fish_git remote 2>/dev/null
+    # Example of output parsed:
+    # "remote.upstream.url git@github.com:fish-shell/fish-shell.git" -> "upstream\tgit@github.com:fish-shell/fish-shell.git"
+    __fish_git config --get-regexp 'remote\.[a-z]+\.url' | string replace -rf 'remote\.(.*)\.url (.*)' '$1\t$2'
 end
 
 function __fish_git_files