Show brief explanation and how-to when non-users click user/post links without Nightweb installed

[taku0]

When non-users click user/post links (i.e. http://nightweb.net/#type=...) without Nightweb installed, the home page of Nightweb is shown. This would confuse he/she since he/she expect to see a user or post.
Showing a brief explanation why he/she sees the page and how to install the Nightweb to see the user/post could relief from the confusion.