Add multilingual language and systems learning tracks

tl/expanded-25-1/lesson-2/main.py

@@ -0,0 +1,5 @@
+a=[[1,2],[3,4]]
+b=[[5],[6]]
+assert all(len(row)==len(b) for row in a)
+out=[[sum(a[i][k]*b[k][j] for k in range(len(b))) for j in range(len(b[0]))] for i in range(len(a))]
+print(out)