Translate "Lab Exercise input1" into Japanese

[ninan27]

Translate "Lab Exercise input1" into Japanese

Description
・Create ja-input1.html
・Add Japanese translations to input1.js
・Fix Japanese translations in checker.js to sound more naturally

[david-a-wheeler]

Hi, we had a merge conflict, which meant we couldn't merge this at all. I attempted to fix the conflict - hopefully this is correct. The problem is that we added a new text line in checker.js.

I'm merging this, as it's much better than what we had before. If my merge conflict fix is in error, please accept my apologies, and please provide a change to correct my error. Thank you so much!

[david-a-wheeler]

Thank you so much!

Note: There are a few spots in the text of ja_input1.html that are still in English and should be in Japanese:

• Button labels (e.g., "Hint")
• Header "Interactive Lab"
• Final line, "This lab was developed by David A. Wheeler at The Linux Foundation."

When you get time, please propose a pull request that fixes them.

[david-a-wheeler]

Also: It's not a requirement, but feel free to translate the code comments into Japanese. You can detect them by looking for text beginning with //.

[david-a-wheeler]

Here are the current values of the Japanese translations in checker.js. I changed these to fix the merge conflict, but they may be wrong. If they are wrong, my sincere apologies. Please provide whatever fixes are appropriate to correct them:

            reset_title: '初期状態にリセットします (現在の試行を破棄します)。',
            to_be_completed: '完了する',
            try_harder_give_up: 'もっと頑張れ！そんなにすぐに諦めないでください>。開始または最後のヒントから経過した現在の時間 (秒単位): {0}',
            try_harder_hint: 'もっと頑張ってください! すぐに諦めないでください。
現在の所要時間 (秒): {0}',