Migration from lighttouch-base to lighttouch

[sh-zam]

• readme needs to be merged by combining git histories, not cp (not in this pr)
• config.lua should be an scl file
• content/* should be ignored since it's the default directory for contentdb databases. please make and move that to another repo and we'll rename or move it later
• home-store.txt needs to move to contentdb.scl move home-store.txt variable to contentdb.scl contentdb#3 which should be included by default in standard lighttouch.scl set env settings variables from app-settings and cwd-settings files jazz#241
• imports.scl needs to be only default stuff

[naturallymitchell]

see issue summary for checklist