Proofreading pass across docs/

[Pashasan]

What

Read through the docs in the docs/ folder and fix any typos, grammar issues, broken links, or unclear sentences you find. Same goes for the top-level guides (README.md, CONTRIBUTING.md, SECURITY.md, CODE_OF_CONDUCT.md, references/README.md) and per-game docs under simulation-games/*/docs/.

Why this is a good first issue

• Bounded scope — there's a finite set of docs to read; you don't need to understand the whole codebase
• No setup required — you can do this entirely in the GitHub web UI (see docs/FIRST_CONTRIBUTION.md Path A)
• Valuable — clear docs are how new contributors get oriented; every typo or stale link makes the project harder to use

Suggested approach

1. Pick one or two docs to start (don't try to do everything at once)
2. Read them carefully; note anything that's unclear, wrong, or out of date
3. Open a PR per file (or per logical group of files) with the fixes
4. Reference this issue in the PR description with "Refs Proofreading pass across docs/ #1"

Multiple contributors are welcome to claim different files — comment which doc(s) you're working on so we don't duplicate.

What "done" looks like

Doesn't need to be exhaustive. Even a single PR fixing a handful of typos in one doc is a useful contribution and closes part of this issue.