Add more entries to robots.txt

[YoshiRulz]

It should be apparent why each of these isn't useful to crawl.

• Might want to keep /Wiki/ViewSource for archival purposes?
• Might want to block /Forum/Posts/User/ for humans who aren't logged in?
• The false positive thing: spec, Google's nicer docs

[Masterjun3]

• Why disallow /Account/? It makes sense to me that people would google "tasvideos register" to find how to register an account.
• And /Forum/Topics/Create/ needs authorization so we don't need to block it here. Otherwise I wonder why you don't also block wiki editing, post creation, userfile creation, and all the other creation stuff. Seems too much.
• Why block /Forum/Posts/User/ ?
• I don't understand the TODO. We know each entry has an implicit trailing wildcard, that's why we can block /Movies- e.g.

[YoshiRulz]

1. Oh right, I'll revert that.
2. It was in a list of highest-trafficked pages you shared recently. I think those others should be blocked, but if you don't want them listed here, I did have a solution using rel="nofollow" in another branch.
3. This was also in said list. It's not really a useful thing to index: crawling /Forum/Topics/{id} will include the posters' names with their posts, so in theory they should be searchable that way if someone wanted. But I think searching by poster is prone to abuse, hence my suggestion in OP.
4. The "correct" way is to put a $ after the path fragment (and then if there are subpages, include a separate .../* entry). I haven't bothered.

[adelikat]

2. I would recommend not listing this or any page that is auth required as it is not necessary and there are too many others. Robots will not be logged in. Also, I think usage statistics doesn't need to play a high role here. If it makes sense for something to be crawled, it should be crawled. If it needs to be more performant as a result, we can address that

4. Then at least put that information in the comment, so that someone who isn't an expert in robot crawling can do the comment. But I would recommend not bothering with it

[Masterjun3]

I have commited some removals as discussed, so that this PR can be merged.