Merge pull request #1042 from julthep/patch-2

Minor update: insert link for Opera

Author: fpscan

docs/guides/core-list.md

@@ -149,7 +149,7 @@
 | Oberon                    | Oberon RISC machine    | An emulator for the Oberon RISC machine, ported to libretro |
 | OpenLara                  | Game engine            | A port of the OpenLara free/open re-implementation of the engine used by the original Tomb Raider series |
 | OpenTyrian                | Game                   | A port of the OpenTyrian clone of the classic Tyrian shmup, ported to libretro |
-| Opera                     | 3DO                    |                    |
+| [Opera](https://docs.libretro.com/library/opera/)             | 3DO                    |                    |
 | ParaLLEl N64              | Nintendo 64            |                    |
 | PascalPong                | Game                   | A free and basic clone of the classic Pong game, written for libretro |
 | PCem                      | IBM PC                 |                    |