add github link and favicons

[luckyyang]

@happypeter why the favicon does not display?

[happypeter]

@luckyyang Old favicon is cached, so new icon has to wait for the old one to expire. but if you use a different name, usually the new one will show up immediately.

[happypeter]

favicon showed up in my browser.

[elsalong]

still old favicon in mine

[happypeter]

@elsalong so you need MAYBE clear your local browser cache. But sometimes, I am not sure, it seems it's your ISP that is doing the cache.

Anyway, just wait for a few days :smile:

[luckyyang]

现在我这也能显示出来，为什么deploy上去就可以了呢？本地测试怎么都不出来，还好我没继续纠缠，难道这也是cache的问题？ maybe， I think。

[luckyyang]

[happypeter]

@luckyyang the way browser to check whether something is cached, is not by the filename, but rather the URL.

so for the browser a.com/thefile and b.com/thefile are different things.

[elsalong]

all right mine is the latest favicon now, done.

[elsalong]

just wonder why only use it on TCOOL, not all page?

[happypeter]

@elsalong yes, why not? Let's.

[luckyyang]

我测试的时候，在本地把cache清理一下，应该就出来了。