Add Ability to Inspect Iframes

[gwwar]

This devtool script executes from the top page context. This means that when inspecting elements in a child iframe, $0 (the currently selected element) returns null.

If folks have pointers on how to pass along this info. It'd be appreciated. I might be able to communicate via an injected content script, but those scripts don't have access to any of the chrome apis.

[gwwar]

Keeping this open until the new release is accepted in the chrome web store

[gwwar]

Closed by #21 and #22

CleanShot.2021-11-18.at.09.44.18.mp4

This is available at https://chrome.google.com/webstore/detail/z-context/jigamimbjojkdgnlldajknogfgncplbh in version 2.0