3 The Docs Editor will be presented by Docs in a sandboxed iframe via for example docs-editor.proton.me.
5 The editor establishes a bidirectional line of communication with the parent Docs client via the PostMesasge API.
7 More information can be found in the design doc here: https://confluence.protontech.ch/pages/viewpage.action?pageId=182012028#ProtonDocsDesignDocClientandAPI-Editorsandbox