moneropedia changes and fixes

_includes/footer.html

_plugins/moneropedia.rb

_plugins/plugin.rb

_strings_en.yml

home.php

knowledge-base/moneropedia/account.md

knowledge-base/moneropedia/block.md

knowledge-base/moneropedia/blockchain.md

knowledge-base/moneropedia/change.md

knowledge-base/moneropedia/transaction.md

knowledge-base/moneropedia/unlocktime.md