Setup JuliaFormatter + reviewdog/action-suggester

Author: tkf

.JuliaFormatter.toml

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+always_for_in = true

.github/workflows/JuliaFormatter.yml

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+name: Code style
+
+on:
+  pull_request:
+
+jobs:
+  JuliaFormatter:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@v1
+      - name: Install dependencies
+        run: |
+          using Pkg
+          Pkg.add("JuliaFormatter")
+        shell: julia --color=yes {0}
+      - name: Format Julia files
+        run: |
+          using JuliaFormatter
+
+          base = ENV["GITHUB_BASE_REF"]  # "main"
+          run(`git fetch origin $base`)
+
+          cmd = `git diff -z --name-only origin/$base`
+          files = split(read(cmd, String), '\0')
+          filter!(endswith(".jl"), files)
+
+          println("Formatting:")
+          foreach(println, files)
+
+          format(files)
+        shell: julia --color=yes --compile=min -O0 {0}
+      - name: suggester / JuliaFormatter
+        uses: reviewdog/action-suggester@v1
+        with:
+          tool_name: JuliaFormatter