MVP implementation of audio feedback / voice messaging

[Jan0707]

We would like to enable our listeners to leave us voice messages for feedback, questions, etc.
(With the idea being that we could then integrate these messages into our episodes - if fitting)

Eventually, we could build this functionality ourselves and upload the messages to our backend. This MDN demo app already outlines most of the frontend work required: https://developer.mozilla.org/en-US/docs/Web/API/MediaStream_Recording_API/Using_the_MediaStream_Recording_API

For the evaluation of this idea however we deem it sufficient to use an external provider, such as Speakpipe or PodInbox - both of whom provide widgets (via iframes) for integration in our website. (Accounts for these services are already created)