lowercased "blog plugin"

docs/setup/setting-up-a-blog.md

@@ -33,7 +33,7 @@ plugins:
 ```
 
 If you do not have a navigation (`nav`) definition in your `mkdocs.yml` then
-there is nothing else to do there as the Blog plugin will add navigation
+there is nothing else to do there as the blog plugin will add navigation
 automatically. If you do have a navigation defined then you need to add *the
 blog index page only* to it. You need not and should not add the individual
 blog posts. For example: