With this commit, we're only allowing users who can create articles to
enter RSS feed information for fetching of articles.
Note: I chose not to indent body of the if conditional to ease the code
review. I also chose to place the if statement in this partial instead
of in the [app/views/users/_extensions.html.erb][1] file; this helps
contain the logic around the policy.
For sleuthing this mirrors the approach of forem/forem#16735Closesforem/forem#16788
Related to forem/forem#16766, forem/forem#16732, and forem/forem#16763
[1]:b87fd77992/app/views/users/_extensions.html.erb (L3)
3ddea544d7