I found a quite interesting software.
This is a stand-along software rather than a browser extension.
You can download it here.
www.listary.com/text-editor-anywhere
Once install and run, you can set a hotkey for it and add your own editor.
Then within a text field in browser, press the hotkey.
A dropdown will be shown, you can select the editors from here by pressing
the hotkey again.
Then, you can edit your text in your favorite editor. Once you save the
text in your editor, it will be synced to the browser.
Quite a useful feature for me, as I do frequently copy text from browser to
VIM and paste it back after editing.