Add draft style guide for the docs site

[mostafaNazari702]

PR Checklist

• Addresses an existing open issue: works on 📝 Docs: Style guide for headings, content, etc. #5446
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Opening this as a draft first to get feedback/approval before doing any larger follow-up renames.

I cooked a short docs style guide in .github/STYLE.md to address #5446 and document the conventions the docs already mostly follow. each rule includes real "good" and "bad" examples pulled from the current docs in the latest main branch.

It covers stuff like:

• sentence-case headings
• action vs concept page naming
• preferred code fence languages (js, bash, ts)
• ESM + node: imports
• avoiding filler/dismissive wording
• consistent version notes, links, filenames, and prose formatting

the goal isnt to invent a brand-new style guide but rather to formalize existing patterns and resolve a few places where the docs are currently inconsistent.

no existing docs are modified yet so review stays focused and low-noise. if the direction looks good i can follow up with separate cleanup PRs for the inconsistencies mentioned at the bottom of the file.

Main feedback I'm looking for:

• Is .github/STYLE.md the right location?
• any rules you'd change/add/remove?
• confirmation on the sentence-case direction before bulk renames.

P.S. AI (GPT-4o) was used responsibly to refine and restructure my original notes into a clearer, more readable format while following the conventions of a Markdown (.md) file.

[mostafaNazari702]

@mark-wiemer @JoshuaKGoldberg
What do you guys say?