Trademark marks and notices for Android and Linux

README.md

@@ -6,7 +6,7 @@ Snowball is an early alpha. Keep your usual copies of anything you can't afford
 
 **[Download the latest release](https://git.tricauda.com/snowball/releases/releases/latest)**. Each release has its notes, and the files below.
 
-## Android, with Obtainium
+## Android™, with Obtainium
 
 Snowball isn't in the Play Store yet. [Obtainium](https://obtainium.imranr.dev) installs it and tells you when there's an update.
 
@@ -19,7 +19,7 @@ When there's a new version, Obtainium offers it. Tap **Update**, and your files
 
 (Or download `snowball-<version>.apk` from a release and open it, but then you won't hear about updates.)
 
-## Linux
+## Linux®
 
 For Ubuntu 22.04, Debian 12, Fedora 36 or anything newer.
 
@@ -33,3 +33,7 @@ To update, quit Snowball from its icon in the top bar, unpack the new release ov
 ## Feedback
 
 Found something wrong, or odd? Email [snowball@temporary.nz](mailto:snowball@temporary.nz).
+
+---
+
+Android is a trademark of Google LLC. Linux® is the registered trademark of Linus Torvalds in the U.S. and other countries.