I want to add a tag to be a grouping or tagging, some types of content I want to focus on and some to read when I have time.

I want to show tag before email Subject.

I know I can edit some email.template for every feedlinks but it`s not a good idea.

Maybe feeds.txt like that:

feeds.txt

https://rss.url/feed1
 - Tag:feed1
https://rss.url/feed2
 - Tag:feed2

But I don't know much about golang.
Have a better idea?