Improve Gerrit v3.8.7 release notes

Add more details to the skeleton of the Gerrit v3.8.7
release notes.

Change-Id: I05f2e657431fe424d442f907ec163e85636ccbc1
diff --git a/pages/site/releases/3.8.md b/pages/site/releases/3.8.md
index a39ec73..6fd8f25 100644
--- a/pages/site/releases/3.8.md
+++ b/pages/site/releases/3.8.md
@@ -727,12 +727,39 @@
 
 * Enhancements
 
+  * [Change 429477](https://gerrit-review.googlesource.com/429477):
+  Update Material Icons, as they were last updated in 2022 and some icons were missing,
+  like the `expand_circle_up`.
+
+  * [Change 399237](https://gerrit-review.googlesource.com/399237):
+  Improved WorkQueue task thread names.
+
 * Bug Fixes
 
-* Plugin changes
+  * [Issue 346618790](https://issues.gerritcodereview.com/issues/346618790):
+  Fix reload of plugins causing incorrect deregistration of dynamic items.
+
+  * [Issue 344608194](https://issues.gerritcodereview.com/issues/344608194):
+  Only suggest hashtags for those matching the input, including also regular
+  expressions.
+
+  * [Issue 343218480](https://issues.gerritcodereview.com/issues/343218480):
+  Fix translation of custom Prolog rules SubmitRecord to SubmitRequirement(s).
 
 * Security Fixes
 
+  * [Change 431197](https://gerrit-review.googlesource.com/431197):
+  Use constant-time comparison for hashed password validation, for increased security
+
+* Documentation Fixes
+
+  * [Change 430957](https://gerrit-review.googlesource.com/430957):
+  Update `prolog-cookbook` documentation mentioning that adding a new `rules.pl` will
+  result in a warning.
+
+  * [Change 424997](https://gerrit-review.googlesource.com/424997):
+  Fix name of `Gerrit-Has-Labels` email footer in documentation.
+
 ### 3.8.6
 
 * Enhancements