Update edX Learner Guide pages with current edX Support email address

Email from :
______
We have identified a few pages in Docs that still reference outdated Support email addresses:

https://edx.readthedocs.io/projects/edx-guide-for-students/en/latest/SFD_pursue_certs.html

https://edx.readthedocs.io/projects/edx-guide-for-students/en/latest/front_matter/preface.html?highlight=%22info%40edx.org%22

https://edx.readthedocs.io/projects/edx-guide-for-students/en/latest/SFD_pursue_certs.html?highlight=technical%40edx.org

Could you remove any references to "billing@edx.org" or "technical@edx.org" or "Info@edx.org" and replace with a link to https://courses.edx.org/support/contact_us so we can encourage learners to search the help center and/or login before submitting a form request?

Also, if there's an easy way for you to scour other Docs pages that reference one of these addresses and replace those, too, that would be wonderful.

Thanks!
Julia

______

While we are pointing learners to the edX Help Center, there still may be links in courses to the edX Learner Guide. I’d suggest updating these links in both the edX/Open edX Learner Guides to reflect the current support email address mentioned in Julia’s email.