Fix note admonition 2

Author: klamike

docs/src/tutorials/linear.md

@@ -159,7 +159,6 @@ mfopA * sol.u - b
 
 !!! note
 
-
-Note that not all methods can use a matrix-free operator. For example, `LS.LUFactorization()` requires a matrix. If you use an
-invalid method, you will get an error. The methods particularly from KrylovJL are the ones preferred for these cases
-(and are defaulted to).
+    Note that not all methods can use a matrix-free operator. For example, `LS.LUFactorization()` requires a matrix. If you use an
+    invalid method, you will get an error. The methods particularly from KrylovJL are the ones preferred for these cases
+    (and are defaulted to).