Fix#3043.
The order of same-cost transactions in the queue was updated in [rippled 1.8.2](https://github.com/XRPLF/rippled/releases/tag/1.8.2), released in 2021, to address issues with high fees and full transaction queues on the network at the time.
- Change transaction-results/transaction-results/ to not repeat itself,
adding a redirect from the old URL.
- Fix Japanese localization of 'tasks' not being updated to 'how-tos'.
(Translated pages in this subfolder were not being shown as translated
due to the mismatch.)
- Fix unparsed `[base58][]` link in addresses snippet.
For better URLs, the content folder has been renamed 'docs' and all
other files have been moved up a level. Also, non-docs images have been
moved to the static folder at the top level where they belong.
Many relative paths had to be fixed to make this work.
