[questions/qa-html-encoding-declarations] Japanese translation of character encoding

[xfq]

[source] (https://www.w3.org/International/questions/qa-html-encoding-declarations.ja) [ja]

I think we could consider using 文字コード instead of 文字エンコーディング, as 文字コード seems to be more commonly used, @himorin what do you think?

[xfq]