Article Update: Safari keyboard navigation

Created by: erinoerin

Proposal for 3 Updates:

1. Rename article. This article covers keyboard navigation for all browsers on MacOS, not just Safari. Suggested name: Browser Keyboard Navigation in MacOSX. (Alternatively: make a new article for each browser)
2. Screenshots are now out of date. As of Catalina, there is only one option: "Use keyboard navigation to move focus between controls". Suggestions: Either replace the screenshot, or add an up-to-date version alongside older one.
3. Firefox. I'm not sure if/when checking the "Use keyboard navigation..." in Settings > Keyboard shortcuts became insufficient, but firefox will not tab to links (firefox 70, Catalina). To fix this, add the accessibility.tabfocus config item and set it to 7 in firefox about:config. I am guessing that Firefox accessibility.tabfocus is 2 (Give focus to all form elements except text fields) even when "Use keyboard navigation..." is set, so links still wouldn't receive focus.

I am happy to update the article