Adds instructions for running Vale locally

.CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contribute to the Polkadot Developer Docs
 
-The documentation source files are written in [Markdown](https://daringfireball.net/projects/markdown) and generally follow the [PaperMoon style guide](https://github.com/papermoonio/documentation-style-guide/blob/main/style-guide.md). If the PaperMoon style guide does not provide explicit guidance on a particular subject, please default to the [Google developer documentation style guide](https://developers.google.com/style).
+The documentation source files are written in [Markdown](https://daringfireball.net/projects/markdown) and generally follow the [PaperMoon style guide](https://github.com/papermoonio/documentation-style-guide/blob/main/style-guide.md). If the PaperMoon style guide doesn't provide explicit guidance on a particular subject, please default to the [Google developer documentation style guide](https://developers.google.com/style).
 
 This guide covers how to contribute to the documentation, including serving a local version of the site, adding new pages and directories, managing images and code snippets, and a few SEO tips.
 
@@ -18,6 +18,7 @@ This guide covers how to contribute to the documentation, including serving a lo
 - [Adding Code and Text Snippets](#adding-code-and-text-snippets)
 - [Adding Images](#adding-images)
 - [Optimizing for SEO](#search-enging-optimization-seo)
+- [Tools for Editing](#tools-for-editing)
 
 ## Viewing Site Locally
 
@@ -27,9 +28,9 @@ You may want to spin up a local version of the documentation site to preview you
 
 Building and serving the site requires cloning two repositories:
 
-- **[Polkadot MkDocs](https://github.com/papermoonio/polkadot-mkdocs)** - contains the MkDocs config files, theme overrides, and custom CSS for the Polkadot documentation site
+- **[Polkadot MkDocs](https://github.com/papermoonio/polkadot-mkdocs)** - contains the MkDocs configuration files, theme overrides, and custom CSS for the Polkadot documentation site
 
-- **[Polkadot Docs](https://github.com/polkadot-developers/polkadot-docs)** - the actual content is stored in the polkadot-docs repo and pulled into the polkadot-mkdocs directory during build
+- **[Polkadot Docs](https://github.com/polkadot-developers/polkadot-docs)** - the actual content is stored in the `polkadot-docs` repository and pulled into the `polkadot-mkdocs` directory during build
 
 For everything to work correctly, the file structure needs to be as follows:
 
@@ -65,7 +66,7 @@ To set up the structure, follow these steps:
 
     This command will install all dependencies listed in the `requirements.txt` file.
 
-2. In the polkadot-mkdocs folder (which should be the current one), you can build the site by running:
+2. In the `polkadot-mkdocs` folder (which should be the current one), you can build the site by running:
 
     ```bash
     mkdocs serve
@@ -127,7 +128,7 @@ If you are adding pages to an existing section, the steps are simplified. Howeve
 - Add the new markdown page to the appropriate section. Note that the filename becomes part of the URL for this page. See the [style guide](https://github.com/papermoonio/documentation-style-guide/blob/main/style-guide.md#naming-conventions) for additional guidance on naming conventions.
 - Ensure the new content page includes the following:
     - **`title`** - represents the `<title>` tag and is used for SEO purposes (not displayed on the published site) Titles have a maximum length of 45 characters.
-    - **`description`** - represents the meta-description and is also used for SEO purposes (not displayed on the published site). Descriptions should be between 120-160 characters and should provide a preview into the page topic.
+    - **`description`** - represents the meta-description and is also used for SEO purposes (not displayed on the published site). Descriptions should be 120-160 characters and should provide a preview into the page topic.
     - **Page title** - an H1 heading title to be displayed at the top of the page
 
     - **`## Checking Prerequisites` section** - if the guide requires the user to have specific developer tools installed, for example, Docker or MetaMask, it should be listed here
@@ -168,7 +169,7 @@ More resources for [SEO Optimization](#search-engine-optimization-seo) of titles
 3. Once you commit and push all of your changes, open a pull request for the new content branch against the `main` branch
 4. Monitor notifications and pull requests for feedback from code owners. At least one approval is required before merging content
 
-If your additions or modifications are limited to content on an existing page, there is no need to worry about the [`.pages`](#example-pages-file) or [`index.md`](#example-indexmd-file) files, as changes to page content do not affect these files.
+If your additions or modifications are limited to content on an existing page, there is no need to worry about the [`.pages`](#example-pages-file) or [`index.md`](#example-indexmd-file) files, as changes to page content don't affect these files.
 
 ## Adding Code and Text Snippets
 
@@ -208,3 +209,28 @@ Here are some resources to help you create good titles and descriptions for SEO:
 - [Google's recommendation on good descriptions](https://developers.google.com/search/docs/advanced/appearance/snippet?hl=en)
 
 In general, titles should be between 50 and 60 characters and descriptions should be between 120 and 160 characters.
+
+## Tools for Editing
+
+There are a few tools you may find useful for proofreading and editing your contributions:
+
+- **[Vale](https://vale.sh/)** - the `polkadot-mkdocs` repository contains configuration for Vale, an open source NLP-powered linter for text. The configuration is a work in progress with a growing custom dictionary tailored toward software engineering, blockchain, and Polkadot terms. Running Vale against your files locally can serve as a first round of feedback to speed up the review process. 
+
+To use Vale locally to screen your work:
+
+1. Visit the Vale site and follow the [installation instructions](https://vale.sh/docs/vale-cli/installation/) 
+2. From the `polkadot-mkdocs` directory run the following in your terminal:
+
+```bash
+  vale (INSERT_PATH_TO_FILE)
+```
+
+The output will look something like:
+
+![Vale sample terminal output](images/contributing/vale-output-01.webp)
+
+3. You can use CMD+click to open the file with the flagged items. This is especially helpful if you run Vale against a directory with multiple files
+
+4. Each flag tells you the line and location of the flagged item, the level of the flag (error, warning, or suggestion), and a suggestion for how to resolve the flag
+
+5. Once you have addressed the flagged items, and made edits as needed, you can complete the normal steps to commit your changes and open a pull request to review for merge