Remove references to webglimpse.net

[ryandesign]

There are four references to webglimpse.net in three files in this repository. That web site no longer exists so those references should be replaced with references to wherever that information can now be found.

[Wikinaut]

Just as info:

• https://github.com/gvelez17

and specifically

• https://github.com/gvelez17/webglimpse
• https://github.com/gvelez17/glimpse