Update known-instances.md to include SquirrelJME (#643)

Include SquirrelJME, which is an emulator for Java ME 8.

Signed-off-by: Stephanie Gawroriski <[email protected]>

Author: XerTheSquirrel

docs/docs/user/known-instances.md

@@ -41,6 +41,7 @@ This page contains a non-exhaustive list with all websites using Anubis.
 - https://minihoot.site
 - https://catgirl.click/
 - https://wiki.dolphin-emu.org/
+- https://squirreljme.cc/
 - <details>
   <summary>FreeCAD</summary>
   - https://forum.freecad.org/