Update 'README.md'

README.md

@@ -1,5 +1,13 @@
-This is a build variant with PostgreSQL including [count_bits](https://github.com/sldab/count-bits). 
+# This is a build variant with PostgreSQL including [count_bits](https://github.com/sldab/count-bits). 
 
 There are no other differences with `static-dockerhub` setup.
 
 Look here for more information: https://git.tt-rss.org/fox/ttrss-docker-compose/src/static-dockerhub/README.md
+
+# FAQ
+
+## How do I create functions on existing database?
+
+`
+docker-compose exec --user postgres db sh -c "cd /opt/count-bits ; make create_functions"
+`