Correct licensing: GNU Free Documentation License 1.2.

As can be verified using http://archive.org to view old copies of the website, the wiki content was licensed under the "GNU Free Documentation License 1.2." http://www.gnu.org/licenses/old-licenses/fdl-1.2.html (since superceded by v1.3), e.g.

* https://web.archive.org/web/20060613062104/http://biopython.org:80/wiki/Main_Page (oldest)
* https://web.archive.org/web/20160330125201/http://biopython.org:80/wiki/Main_Page (most recent)

We'd need to check with the contributors since the GitHub migration, and then update the new template here which currently says "All rights reserved.":
https://github.com/biopython/biopython.github.io/blob/master/_includes/sidebar.html#L51

Reported by @hlapp by email.

從所引用行的 _includes/sidebar.html 開始，將目前的授權文字與 issue 中連結的已封存 Main_Page 副本進行比較。在修改之前，請依要求先與貢獻者確認；完成的標準是側邊欄反映已確認的 GNU Free Documentation License 版本，而不是「All rights reserved.」。

由索引模型根據 Issue 內容生成。