Greasy Fork

Update find button logic to use regex

add a fallback match for roughly attempting to match if the regular match fails (may need to add more match options in the future to get all the cases)

- remove the console log for previous and next button match result

- Fix sites that use << and >> but not class identifiers for buttons
- Fix sites that short-form Chapter to chap (found one that short-forms Chapter but not Previous... why?)

update namespace to link back to greasyfork page for WN Navigation