I am building an email template using HTML and I was wondering if I can place a repeat block in HTML to view a list of rows. 
I know if I use Visualforce template I can achieve my goal using <apex:repeat>, but I would like to know if it is possible using just HTML.

Is it possible to create an email template with LWC? Currently, I am using a VF or pure HTML to create such templates.

what is the difference between; 
force:mdapi vs force:source.
force:mdapi:retrieve vs force:source:retrieve and force:source:pull