[revert] recover "[refactor] restructure configuration files (#2977)" (#3022)

This reverts commit 35c8f4ce47.

.clang-format

@@ -0,0 +1 @@
+BasedOnStyle: Google

.isort.cfg

@@ -0,0 +1,5 @@
+[settings]
+line_length = 120
+multi_line_output=3
+include_trailing_comma = true
+ignore_comments = true

.pre-commit-config.yaml

@@ -11,14 +11,13 @@ repos:
     hooks:
     - id: yapf
       name: yapf formatter
-      args: ['--style=pyproject.toml', '--parallel', '--in-place']
+      args: ['--style=.style.yapf', '--parallel', '--in-place']
 
   - repo: https://github.com/pre-commit/mirrors-clang-format
     rev: v13.0.1
     hooks:
     - id: clang-format
       name: clang formatter
-      args: [--style, "{BasedOnStyle: Google}"]
 
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.3.0

.style.yapf

@@ -0,0 +1,5 @@
+[style]
+based_on_style = google
+spaces_before_comment = 4
+split_before_logical_operator = true
+column_limit = 120

pyproject.toml

@@ -1,19 +0,0 @@
-[tool.isort]
-line_length = 120
-multi_line_output = 3
-include_trailing_comma = true
-ignore_comments = true
-
-[tool.yapf]
-based_on_style = "google"
-spaces_before_comment = 4
-split_before_logical_operator = true
-column_limit = 120
-
-[tool.pytest.ini_options]
-markers = [
-    "cpu: tests which can run on CPU",
-    "gpu: tests which requires a single GPU",
-    "dist: tests which are run in a multi-GPU or multi-machine environment",
-    "experiment: tests for experimental features",
-]

pytest.ini

@@ -0,0 +1,6 @@
+[pytest]
+markers =
+    cpu: tests which can run on CPU
+    gpu: tests which requires a single GPU
+    dist: tests which are run in a multi-GPU or multi-machine environment
+    experiment: tests for experimental features