add: customizable-hotkey-plus-code-refactor

[Metacor]

refactored the codebase

• reduced the number of nested functions and limited the maximum nesting level
• made the query creation functions modular instead of writing them twice for Jap & Eng
• "awaitLoadOf" now properly targets the required title info, instead of just reloading until it works
• these changes about as close to "breaking" as this type of program can get; updating to v2.0.0

added a secondary settings page, accessible by clicking the cog icon within popup.html

• added an option to not render the "Search on Nyaa" button
• added a customizable hotkey that will open the search when pressed (even if the button is hidden)
  • on card-type pages this only opens the first link; any attempt to allow batch openings just resulted in HTTP "429 Too Many Requests" errors for most of the pages, and using delays just made it super awkward
• added an option to change the tab focus behavior when using the hotkey
  • enabled = focus stays on the current tab | disabled = changes focus to the Nyaa tab

fixed MAL card-type pages to allow for multiple titles (I incorrectly thought there could only be one title per card) fixed issues with the button not rendering on Kitsu depending on the user's login state fixed errors on AniDB and Anime-Planet for non-series pages that start with /anime/ or /manga/

updated README.md

• updated the banner image; more uniform sizes with better separation, and different shows for each site: old | new
• updated the extension popup screenshot to show the updated functionality
• updated the site preview images to show more of the website instead of just the panels
  • added additional site previews for the newly supported card-type pages