Turn off cd abbreviations by default (#7536)

# Description

This turns off `cd` abbreviations by default

# User-Facing Changes

`cd` goes back to requiring a name with the default configuration

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-utils/src/sample_config/default_config.nu

@@ -307,7 +307,7 @@ let-env config = {
     always_trash: false # always act as if -t was given. Can be overridden with -p
   }
   cd: {
-    abbreviations: true # allows `cd s/o/f` to expand to `cd some/other/folder`
+    abbreviations: false # allows `cd s/o/f` to expand to `cd some/other/folder`
   }
   table: {
     mode: rounded # basic, compact, compact_double, light, thin, with_love, rounded, reinforced, heavy, none, other