add 7 seg decoder

project_urls.py

diff --git a/project_urls.py b/project_urls.py
index 4db00db..a3a631a 100644
--- a/project_urls.py
+++ b/project_urls.py
@@ -5,4 +5,5 @@
             'https://github.com/mattvenn/wokwi_inverters',
             'https://github.com/wokwi/tiny-tapeout-test-simple',
             'https://github.com/omerk/tinytapeout-demo1',
+            'https://github.com/mattvenn/tinytapeout-7seg-decoder',
     ]