further parallax effect updates

- limit parallax effect only to circles within window viewport
- refine parallax effect
remove some debug code
removed stroke styling options; added sumbit-on-enter functionality
minor updates

- renamed hybrid to stroke
- refined parallax style
- styled save button
add ability to turn off parallax
- "hide article content" is now "show article content"
- toggling content visibility is now dynamic
- this setting is saved automatically with checkbox interaction
- bug fixes
bug fixes

contentIsVisible is not set correctly
extension update, easy access to oft-edited variables

- saved out for latest extension (version .202)
- created/organized oft-edited variables at the top for easy access