Fix some filename/URL issues.

- 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.

@i18n/ja/docs/tutorials/how-tos/use-tokens/index.md

@@ -0,0 +1,12 @@
+---
+html: use-tokens.html
+parent: tasks.html
+metadata:
+  indexPage: true
+---
+# トークンの利用
+
+XRP Ledgerでトークン(代替型やそれ以外)を発行し、取引しましょう
+
+
+{% child-pages /%}