Add TOML language formatting capability to the project infrastructure

Python package-based tools are used by the infrastructure of this project. The configuration of this Python
infrastructure is defined by the `pyproject.toml` file. This file uses the TOML language.

In addition to the machine entries produced by the Poetry tool, this important file is also edited directly by human
contributors. For this reason, it will be useful to provide code formatting infrastructure for TOML files, and to
enforce consistent formatting. This is easily accomplished by adding TOML support to the existing code formatting
infrastructure via the "prettier-plugin-toml" plugin for the Prettier formatting tool.

Poetry's `poetry.lock` file is also written in the TOML language. This file is automatically generated and never
manually edited. In this case, the automatically generated content is accepted as-is. So Prettier is configured to
exclude the `poetry.lock` file from formatting.

Author: per1234

.github/workflows/check-prettier-formatting-task.yml

@@ -92,6 +92,13 @@ on:
       - "**.mkdn?"
       - "**.ronn"
       - "**.workbook"
+      # TOML
+      - "**/Cargo.lock"
+      - "**/Cargo.toml.orig"
+      - "**/Gopkg.lock"
+      - "**/Pipfile"
+      - "**/pdm.lock"
+      - "**.toml"
       # YAML
       - "**/.clang-format"
       - "**/.clang-tidy"
@@ -189,6 +196,13 @@ on:
       - "**.mkdn?"
       - "**.ronn"
       - "**.workbook"
+      # TOML
+      - "**/Cargo.lock"
+      - "**/Cargo.toml.orig"
+      - "**/Gopkg.lock"
+      - "**/Pipfile"
+      - "**/pdm.lock"
+      - "**.toml"
       # YAML
       - "**/.clang-format"
       - "**/.clang-tidy"

.prettierignore

@@ -1,3 +1,4 @@
 .licenses/
 __pycache__/
 node_modules/
+poetry.lock

.prettierrc.yml

@@ -0,0 +1,2 @@
+plugins:
+  - prettier-plugin-toml

package-lock.json

@@ -5,7 +5,8 @@
     "github-label-sync": "3.0.0",
     "markdown-link-check": "^3.13.7",
     "markdownlint-cli": "^0.44.0",
-    "prettier": "^3.5.3"
+    "prettier": "^3.5.3",
+    "prettier-plugin-toml": "2.0.2"
   },
   "engines": {
     "node": "20.x"