Make new member welcome email more generic

[Sandplum]

New members receive an email when their applications are accepted. The email includes an invitation to attend meetings:

Welcome aboard {{first_name}}!

Great to have you onboard! Your membership application has been
approved and now is a great time to to join our community by
coming to the next community meeting on the first Tuesday of the
month or poping by weekly open house every Tuesday. It is also
highly recommendable to join our communication channels (Matrix,
Telegram or IRC and email list). Be happy to ask if you like to
know more!

The message could be modified to be more generic, and not limited to organizations that have meetings on Tuesdays.

Your membership application has been approved and now is a great time to to join our community by
coming to the next community meeting or popping by during an open house event.

It is also highly recommended to join our communication channels (Matrix and email list). Feel free to ask if you would like to
know more!

The note regarding the bank sync could be updated to reflect actual sync schedule.

Important note about door access! The payment data from bank is synced only once a day and this might
mean that your payment is not seen by the system until the next sync happens. You can check when the last sync happened in {{siteurl}}

[olmari]

Related Issue (kinda prerequisite, not really but practically): #172

[braaar]

I like the idea of making the email much more generic to begin with.

That will force those who want more specificity to do something like #172

[Sandplum]

Agreed. As this issue is currently having a negative effect on one particular organization, I urge the adoption of a quick fix, followed by a more thorough re-design of the email process.