[m-rev.] diff: Advise to create annotated tags.

[Peter Wang]

I didn't want to clutter the text with "why", but for tags that will be
published, it's better to use annotated tags (objects with metadata)
instead of lightweight tags (that are just a name pointing to a commit).
https://stackoverflow.com/questions/4971746/why-should-i-care-about-lightweight-vs-annotated-tags/4971817#4971817

---

compiler/notes/upgrade_boehm_gc.html:
    As above.

diff --git a/compiler/notes/upgrade_boehm_gc.html b/compiler/notes/upgrade_boehm_gc.html
index 71c5ae355..b22bd90d4 100644
--- a/compiler/notes/upgrade_boehm_gc.html
+++ b/compiler/notes/upgrade_boehm_gc.html
@@ -363,7 +363,7 @@ currently using.</li>
 
 <li>Make your changes and commit them.</li>
 
-<li>Add a tag named
+<li>Add an annotated tag (<code>git tag -a</code>) named
 <code>release-<var>M</var>_<var>N</var>-mercury-<var>YYYYMMDD</var></code>
 where <var>YYYYMMDD</var> is the date.</li>
 
-- 
2.39.0