Added stub release notes for 4.1.8.

docs/releases/4.1.8.txt

@@ -0,0 +1,12 @@
+==========================
+Django 4.1.8 release notes
+==========================
+
+*Expected April 3, 2023*
+
+Django 4.1.8 fixes several bugs in 4.1.7.
+
+Bugfixes
+========
+
+* ...

docs/releases/index.txt

@@ -40,6 +40,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   4.1.8
    4.1.7
    4.1.6
    4.1.5