Platform Labels Update (#3581)

* First preview of platform indicators

* Fix

* Update
- Format 2FA section.
- Fix known edge cases.

* Update
- Update Mac & Linux icons.
- Fix icon cut-off bug.

* Remove dependency

* Better icons

* Update
- Labelled PowerShell platforms.
- Updated regex.
- Fixed an edge case.

* Update
- Removed need for trailing `/` at EOL.
- Updated more entries to the new format.

* Deploy for main-4

* Update

* Update
- Added icon for "Web".
- Updated any entries to "All Platforms".
- Formatted "Encrypted Messengers" section.

* Update
- Tidied Song Identification section.
- Some misc changes.

* Update
- Tweaked wording on Contribute guide.

* Undo deploy

* Update

docs/linuxguide.md

@@ -761,7 +761,7 @@
 * [Macs Fan Control](https://github.com/crystalidea/macs-fan-control) - Fan Controller
 * [Find You](https://github.com/positive-security/find-you) - Track Bluetooth Devices
 * [Touché](https://redsweater.com/touche/) - Touch Bar Simulator
-* [Sentinel](https://github.com/alienator88/Sentinel) - SwiftUI Gatekeeper Config GUI / macOS Only
+* [Sentinel](https://github.com/alienator88/Sentinel) - SwiftUI Gatekeeper Config GUI
 * [USBMap](https://github.com/corpnewt/USBMap) - Map macOS USB Ports
 * [Actions](https://sindresorhus.com/actions) - Additional Shortcuts App Actions
 * [pock](https://pock.app/) - Touch Bar Widget Manager / [GitHub](https://github.com/pock/pock)