Added `rustfmt` in GH Workflow, added `rustfmt.toml` and updated `README.md`

.github/workflows/build.yml

@@ -21,12 +21,17 @@ jobs:
       with:
         profile: minimal
         toolchain: stable
-        components: clippy
+        components: clippy, fmt
     - name: Linting (clippy)
       uses: actions-rs/clippy-check@v1
       with:
         token: ${{ secrets.GITHUB_TOKEN }}
         args: --all-targets -- -D warnings -A clippy::all -W clippy::correctness
+    - name: Formatting (rustfmt)
+      uses: actions-rs/cargo@v1
+      with:
+        command: fmt
+        args: --all -- --check --verbose
     - name: Tests (test)
       uses: actions-rs/cargo@v1
       with:

README.md

@@ -48,3 +48,11 @@ Or with `clippy`:
 ```sh
 cargo clippy --all-targets -- -A clippy::all -W clippy::correctness
 ```
+
+To check the **formatting**:
+
+> **NOTE:** remove `--check` to apply the changes to the file(s).
+
+```sh
+cargo fmt --all -- --check
+```

rustfmt.toml

@@ -0,0 +1,36 @@
+# This file defines the Rust style for automatic reformatting.
+# See also https://rust-lang.github.io/rustfmt
+
+# NOTE: the unstable options will be uncommented when stabilized.
+
+# Version of the formatting rules to use.
+#version = "One"
+
+# Number of spaces per tab.
+tab_spaces = 4
+
+max_width = 100
+#comment_width = 80
+
+# Prevent carriage returns, admitted only \n.
+newline_style = "Unix"
+
+# The "Default" setting has a heuristic which can split lines too aggresively.
+#use_small_heuristics = "Max"
+
+# How imports should be grouped into `use` statements.
+#imports_granularity = "Module"
+
+# How consecutive imports are grouped together.
+#group_imports = "StdExternalCrate"
+
+# Error if unable to get all lines within max_width, except for comments and
+# string literals. 
+#error_on_line_overflow = true
+
+# Error if unable to get comments or string literals within max_width, or they
+# are left with trailing whitespaces.
+#error_on_unformatted = true
+
+# Files to ignore like third party code which is formatted upstream.
+#ignore = []