fix some edge cases around multiline attributes

packages/autofmt/src/component.rs

@@ -165,7 +165,14 @@ impl Writer<'_> {
             match &field.content {
                 ContentField::ManExpr(exp) => {
                     let out = prettyplease::unparse_expr(exp);
-                    write!(self.out, "{name}: {out}")?;
+                    let mut lines = out.split('\n').peekable();
+                    let first = lines.next().unwrap();
+                    write!(self.out, "{name}: {first}")?;
+                    for line in lines {
+                        self.out.new_line()?;
+                        self.out.indented_tab()?;
+                        write!(self.out, "{line}")?;
+                    }
                 }
                 ContentField::Formatted(s) => {
                     write!(