Your theme source files should be located in a keycloak-theme directory somewhere in your src directory OR at the root of your directory.
Acceptable directory strucuture:
src/
keycloak-theme/
login/
account/
email/
===OR===
src/
foo/
bar/
keycloak-theme/
login/
account/
email/
===OR===
src/
login/
account/
email/
You don't need to have all three variant of the theme. If you only need the login theme for example you can have only the login directory.