Wiki Improvement (Strengthen warnings about `bx seed`)

[Ademan]

It doesn't look like I can issue PRs against the wiki directly, but I wanted to offer Ademan/libbitcoin-wiki@eef7ca2 as a quick improvement to strengthen the warnings about bx seed due to recent events.

There are a ton of references to bx seed throughout the wiki, and I think arguably all of them should carry warnings similar to what I added, but at the very least, the example on the homepage of the wiki should guide people towards an explanation of bx seed's limitations.

[evoskuil]

Thanks, much appreciated.

[evoskuil]

@kulpreet this seems fine, please “merge” if you concur.

[pool2win]

Happy to merge. @Ademan can you make a pull request please?

Otherwise, I can pick the commit patch and merge. It'll lose attribution that way.

[kulpreet]

Commit merged. Thanks @Ademan

Closing the issue.