[nongnu] elpa/rust-mode 3b81e81: update readme

[ELPA Syncer]

branch: elpa/rust-mode
commit 3b81e81097463e7161de047ad340e4fe572dcc2a
Author: brotzeit <brotzeitmacher@gmail.com>
Commit: brotzeit <brotzeitmacher@gmail.com>

    update readme
---
 README.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 324de96..8aba0e3 100644
--- a/README.md
+++ b/README.md
@@ -80,7 +80,11 @@ And put this in your config to load rust-mode automatically:
 
 ### NonGNU ELPA
 
-https://elpa.nongnu.org/
+[NonGNU ELPA](https://elpa.nongnu.org/) can be used out of the box in
+emacs28.
+
+For older versions you need to add something like the following to
+your init file:
 
 ``` elisp
 (with-eval-after-load 'package (add-to-list 'package-archives '("nongnu" . 
"https://elpa.nongnu.org/nongnu/";)))