docs-util: created docblock-generator tool (#6096)

docs-util/packages/docblock-generator/README.md

@@ -0,0 +1,38 @@
+# docblock-generator
+
+A CLI tool that can be used to generate TSDoc docblocks for TypeScript/JavaScript files under the `packages` directory of the main monorepo.
+
+## Prerequisites
+
+1. Run the `yarn` command to install dependencies.
+2. Copy the `.env.sample` to `.env` and change the `MONOREPO_ROOT_PATH` variable to the absolute path to the monorepo root.
+
+---
+
+## Usage
+
+### Generate for a specific file
+
+Run the following command to run the tool for a specific file:
+
+```bash
+yarn start run /absolute/path/to/file.ts
+```
+
+### Generate for git-changed files
+
+Run the following command to run the tool for applicable git file changes:
+
+```bash
+yarn start run:changes
+```
+
+### Generate for a specific commit
+
+Run the following command to run the tool for a commit SHA hash:
+
+```bash
+yarn start run:commit <commit-sha>
+```
+
+Where `<commit-sha>` is the SHA of the commit. For example, `e28fa7fbdf45c5b1fa19848db731132a0bf1757d`.