Improve documentation for contribution guidelines

- Improve `CONTRIBUTING.md` with clearer, more structured guidelines.
- Introduce a centralized 'Script Guidelines' document for consistent
  reference.
- Remove repetitive information across documents, providing links to the
  primary source.
- Simplify language across related documentation for better
  accessibility and readability.

docs/script-guidelines.md

@@ -0,0 +1,56 @@
+# privacy.sexy Script Guidelines
+
+Create a script for privacy.sexy by submitting a PR or creating an issue (details in [Extend Scripts](./../CONTRIBUTING.md#extend-scripts)).
+As scripts are central to privacy.sexy and reach a global audience, their design is critical.
+
+Key attributes of a good script:
+
+- ✅ Well-referenced [documentation](#documentation).
+- ✅ Utilizes [shared functions](#shared-functions).
+- ✅ Has a [simple name](#name).
+
+## Name
+
+- Choose a title that is easy to understand for all users, regardless of technical skill, yet remains technically accurate.
+- Focus on privacy implications, avoiding complex or overly technical jargon.
+- Maintain consistency in naming, avoiding linguistic variations.
+- Use action-oriented language for clarity and directness. Use an instruction format like "do this, do that" for clear, direct guidance.
+- Respect the official casing of brand names.
+- Choose clear and uncomplicated language.
+- It should start with an imperative noun.
+- Start with action verbs like `Clear`, `Disable`, `Remove`, `Configure`, `Minimize`, `Maximize`. While exceptions exist, these prefixes help maintain naming consistency.
+- Favor the terms:
+  - `Disable` over `Turn off`, `Stop`, `Prevent`
+  - `Configure` over `Set up`
+  - `Clear` over `Erase`, `Clean`
+  - `Minimize` over `Limit`, `Reduce`
+  - `Maximize` over `Extend`, `Delay`, `Postpone`, `Prolong`
+  - `Remove` over `Uninstall`
+- Structure your phrases for clarity, examples:
+  - Prefer `Disable XX telemetry` over `Disable telemetry in XX`
+  - Prefer `Clear XX data` over `Clear data from XX`, or `Clear data of XX`.
+- Use sentence case rather than Title Case.
+
+## Documentation
+
+- Use credible and reputable sources for references.
+- Use archived links by using [archive.org](https://archive.org) or [archive.today](https://archive.today).
+  - Format archive.today links fully, for example: `https://archive.today/YYYYMMDDhhmmss/https://privacy.sexy`.
+- Explain the default behavior if the script is not executed.
+
+## Shared functions
+
+Use existing shared functions when possible, like `DisableService` for disabling services,.
+
+- 📖 Learn about templates in [templating.md](./templating.md).
+- 📖 For syntax, see [collection-files.md](collection-files.md).
+
+## Code
+
+- Prefer [shared functions](#shared-functions); avoid custom code unless necessary.
+- Keep code simple and compatible with older systems.
+- Focus on reliability, ensuring the script is error-resistant, works on different locales and handles unexpected situations.
+- Language selection:
+  - Windows: Use batch when simpler, otherwise PowerShell.
+  - macOS/Linux: Use bash when simpler, otherwise Python.
+- Provide revert code to restore original/default settings when applicable.