Antoine Stevan b964347895
add a test to make sure "nothing" shows up as "nothing" in help (#9941)
related to 
- https://github.com/nushell/nushell/pull/9935

# Description
this PR just adds a test to make sure type annotations in `def`s show as
`nothing` in the help pages of commands.

# User-Facing Changes

# Tests + Formatting
adds a new test `nothing_type_annotation`.

# After Submitting
2023-08-09 05:10:34 +12:00
..