Fix some errors

1. 修正無效連結
/python-console-and-python-api -> /basic-concepts/#python-console-and-python-api

2. 修正沒有正確 close 的 tag
<kbd>Ctrl<kbd> + <kbd>`<kbd> -> <kbd>Ctrl</kbd> + <kbd>`</kbd>
Merge pull request #5 from TuTu/patch-1

修正無效連結及沒有正確 close 的 tag