docs/zh_TW: rewrite index.rst

Update zh_TW's index.rst to the version of commit 0c7b4366 ("docs:
Rewrite the front page") with some reference from commit f4bf1cd4
("docs: move asm-annotations.rst into core-api") and commit eef24f70
("docs/zh_CN: Rewrite the Chinese translation front page").

Signed-off-by: Hu Haowen <src.res.211@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230708054052.45967-1-src.res.211@gmail.com