Searches for text in a tab.
You can use this function to search normal HTTP(S) web pages. It searches a single tab: you can specify the ID of a particular tab to search, or it will search the active tab by default. It searches all frames in the tab.
You can make the search case-sensitive and make it match whole words only.
By default, the function just returns the number of matches found. By passing in the includeRangeData and includeRectData options, you can get more information about the location of the matches in the target tab.
This function stores the results internally, so the next time any extension calls find.highlightResults(), then the results of this find call will be highlighted, until the next time someone calls find().
This is an asynchronous function that returns a Promise.