Supercell is teasing the ability to edit your War Base prior to the start of a Clan War in Clash of Clans. The developer of the popular mobile game today posted a new picture teasing the new feature along with a message that reads "Hey Chief! Been wanting to keep a separate layout for your War Base? Soon you can!!!!"
In the current Clan Wars format, your War Base is automatically generated to match your main village layout at the end of the Preparation Day. This can make things quite annoying for those who move their town hall to outside of their walls when not at war. This new editor should remove that annoyance as you should soon be able to create an entirely separate layout specifically for Clan Wars. It's unclear when this new feature will be enabled, but hopefully soon.
Clan Wars has been active in Clash of Clans since early April. You can read a full overview of the mode here.