Recipe listing has wrong indentation when nested modules are used

[vlaci]

Consider the following layout:

.
├── a.just
├── b.just
└── justfile

# a.just

mod b

top-level:
    @echo top

# b.just

nested:
    @echo "nested"

# justfile

mod a

The output for the mid-level b module is misaligned, suggesting that b is available at the top level:

$ just --unstable --list
Available recipes:
    a:
        top-level
    b:
            nested