zh-TW：Add missing translation for 'Collab Summit'

[ghost]

Add this missing Traditional Chinese for 'Collab Summit'.

[osk2]

I'm thinking that if it's necessary to translate "Collab Summit". if so, then we'll need to translate words in collab-summit.md too.

[ghost]

collab-summit.md has been translated into zh-TW as：https://nodejs.org/zh-tw/get-involved/collab-summit/.

You see that we've translated once about "Collab Submmit" as "協作者峰會". And for the rest, there's no need to translate because they are fixed special pharses.

[osk2]

I mean the word "Collab Summit" :P

I left them untranslated in collab-summit.md. If we decide to translate them to "協作者峰會", we should also replace "Collab Summit" with "協作者峰會" in collab-summit.md.

[osk2]

Nice, looks much better now 👍