Problem:
When running ":edit <url>", filetype detection is not triggered.
Solution:
Run the autocmds in the filetypedetect group after loading the content.
Problem:
After fetching remote content from a URL and adding it to the buffer,
the buffer is marked as modified. This is inconsistent with the original
netrw behavior, and it causes problems with `:e` to refresh or `:q` as
it prompts for saving the file even if the user hasn't touched the
content at all.
Solution:
Mark the buffer as unmodified right after adding the remote content to
the buffer.
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