chore: set toolchain to nightly (#52)

Description
---
- Set toolchain to nightly
- Set `newline_style = "Auto"` to not fight with git settings

Motivation and Context
---
- `cargo build --release`, `cargo check`, etc. failed

How Has This Been Tested?
---
Compiled locally without the `cargo +nightly` switch

What process can a PR reviewer use to test or verify this change?
---

<!-- Checklist -->
<!-- 1. Is the title of your PR in the form that would make nice release
notes? The title, excluding the conventional commit
tag, will be included exactly as is in the CHANGELOG, so please think
about it carefully. -->


Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

<!-- Does this include a breaking change? If so, include this line as a
footer -->
<!-- BREAKING CHANGE: Description what the user should do, e.g. delete a
database, resync the chain -->

rust-toolchain.toml

@@ -1,2 +1,2 @@
 [toolchain]
-channel = "stable"
+channel = "nightly"

rustfmt.toml

@@ -4,7 +4,7 @@ edition = "2021"
 hard_tabs = false
 match_block_trailing_comma = true
 max_width = 120
-newline_style = "Native"
+newline_style = "Auto"
 reorder_imports = true
 reorder_modules = true
 use_field_init_shorthand = true