Add AutoIndent action and '=' vim operator (#21427)

Release Notes:

- vim: Added the `=` operator, for auto-indent

Co-authored-by: Conrad <conrad@zed.dev>

crates/vim/src/vim.rs

@@ -470,6 +470,7 @@ impl Vim {
                 | Operator::Replace
                 | Operator::Indent
                 | Operator::Outdent
+                | Operator::AutoIndent
                 | Operator::Lowercase
                 | Operator::Uppercase
                 | Operator::OppositeCase