Use npm to manage Prettier tool dependency (#254)

The project uses the Prettier tool to format various file types. Previously, the version of the tool used was not
controlled. This was problematic because:

- A different version of the tool may be used on the contributor's machine than on the CI runner, resulting in confusing
  failures.
- The project is immediately subject to disruption or breakage resulting from a release of the tool.

The new approach is to specify the version of the tools via the standard npm metadata files (package.json +
package-lock.json), providing the following benefits:

- Enables automated updates via Dependabot PRs
- Enables automated vulnerability alerts

.prettierignore

@@ -11,3 +11,4 @@ indexes/testdata/package_index.json
 
 # Generated files
 /.licenses/
+node_modules/

Taskfile.yml

@@ -47,6 +47,8 @@ tasks:
   # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-prettier-formatting-task/Taskfile.yml
   general:format-prettier:
     desc: Format all supported files with Prettier
+    deps:
+      - task: npm:install-deps
     cmds:
       - npx prettier --write .
 

package.json

@@ -1,6 +1,7 @@
 {
   "devDependencies": {
     "markdown-link-check": "^3.12.1",
-    "markdownlint-cli": "^0.37.0"
+    "markdownlint-cli": "^0.37.0",
+    "prettier": "^3.3.3"
   }
 }