l10n: ja: Change about/more link text (#3539)
l10n: ja: Change about/more link text (#3539)

ref: #3538 ("Extended information" -> "About this instance") and #3519

Signed-off-by: lindwurm <9e0c477f7abb875a958abf29dc2f25e97b75e0fe@gmail.com>
kibousoft/mastodon,kibousoft/mastodon,kibousoft/mastodon,kibousoft/mastodon