Add documentation for using SDC with Experience Builder

I tried to make this user guide as interesting as I could for an XB beginner.

Feel free to improve it, and correct all my language mistakes 📝

For the record, this is one of those issues where gitlab env depends on who triggers the job, if it's a maintainer or not. See 📌 Allow testing documentation pages via MRs Active

akhil babu → made their first commit to this issue’s fork.

I'm afraid this needs a new MR against canvas 🙈😬