* Initial beta modal set up
* Add back to old pki from engine
* Remove commented out code
* Add stylesheet and tests!
* Address feedback!
* Add id to input
* rename download service file
* rename file again
* add download-file service to engine
* refactor download button to use service
* refactor download service
* finish refactor download service, make arg order consistent: filename, content, extension
* add download button to key details
* fix flaky test?
* setup PKI Ember engine
* clean up SecretListHeader and add documentation.
* move secret-list-header to addon folder
* move options-for-backend helper
* fix all for SecretListHeader to work
* use secretListHeaderTab by moving to adodn.
* add overview empty state
* clean up
* remove secret-list-header and secret-list-header-tab changes to move to another pr
* more cleanup
* update syntax with newer guides
* good idea jordan
