HTMLDocument.registerElement is deprecated.

[LJacki]

Use customElements.define instead of document.registerElement see https://javascript.info/custom-elements

HTMLDocument.registerElement (file:///C:/Users/Jack/AppData/Local/atom-beta/app-1.61.0-beta0/resources/app.asar/static/index.js:160:12)
registerElement (C:\Users\Jack\.atom\packages\editor-background\node_modules\space-pen\lib\space-pen.js:66:88)
Builder.openTag (C:\Users\Jack\.atom\packages\editor-background\node_modules\space-pen\lib\space-pen.js:297:27)
Builder.tag (C:\Users\Jack\.atom\packages\editor-background\node_modules\space-pen\lib\space-pen.js:274:12)
Function.div (C:\Users\Jack\.atom\packages\editor-background\node_modules\space-pen\lib\space-pen.js:83:49)
Function.content (C:\Users\Jack\.atom\packages\build\lib\build-view.js:35:12)