I don’t think you can do this with pure Shortcuts, but you can run an AppleScript:
tell application "Safari"
set docText to ""
set tabcount to number of tabs in the front window
--Repeat for Every Tab in Current Window
repeat with y from 1 to tabcount
--Get Tab Name & URL
set tabName to name of tab y of the front window
set tabURL to URL of tab y of the front window
set docText to docText & "- [" & tabName & "](" & tabURL & ")" & linefeed as string
end repeat
set the clipboard to docText
end tell
This gets the links from the front window in Markdown in a list, I suspect you could modify it further!