It is possible to create custom neo4j browser guide and run it.
Ex: :play http://guides.neo4j.com/graphgist/restaurant_recommendation.html.
Also neo4j has default browser guides like :play cypher.
I want to make my neo4j guide as built in guide like :play mycustomguide
How can I do it?
That's only possible for guides that currently reside on guides.neo4j.com
You'd have to patch the browser code for that. github.com/neo4j/neo4j-browser
But you can configure in neo4j.conf a start command that allows you to play your guide automatically at the beginning, see:
https://neo4j.com/developer/guide-create-neo4j-browser-guide/