README.md: add copyright notice

README.md

@@ -14,14 +14,14 @@ in the likes of several other entries from the mid 90's.
 The following platforms are either supported or support is expected in
 the future:
 
-- Sony PlayStation 1, using a forked version of
+- Sony® PlayStation® 1, using a forked version of
 [PSXSDK](https://git.disroot.org/xavi92/psxsdk).
-- Microsoft Win9x, using a `i386-mingw32` cross-toolchain and SDL-1.2.
+- Microsoft® Win9x, using a `i386-mingw32` cross-toolchain and SDL-1.2.
 A `i386-mingw32` cross-toolchain must be already available on the
 system.
-- POSIX-compliant operating systems such as GNU/Linux or *BSD, using
+- POSIX-compliant operating systems such as GNU/Linux® or *BSD, using
 SDL-1.2 (if available).
-- Possibly, modern Microsoft Windows versions, too (currently
+- Possibly, modern Microsoft® Windows® versions, too (currently
 untested).
 
 ## Design goals
@@ -58,9 +58,9 @@ make -j$(nproc --all)
 can be used to set up the cross-toolchain. Files labeled as
 `cmake/*-toolchain.cmake` can be used as values.
 
-#### Sony PlayStation 1
+#### Sony® PlayStation® 1
 
-For example, the Sony PlayStation 1 version can be built using:
+For example, the Sony® PlayStation® 1 version can be built using:
 
 ```sh
 mkdir build
@@ -75,7 +75,7 @@ This will generate a `.bin`/`.cue` file pair in `build` that can be
 played on an emulator or burnt into a CD-r in order to play the game
 on real hardware.
 
-#### Microsoft Win9x
+#### Microsoft® Win9x
 
 ```sh
 mkdir build
@@ -100,3 +100,8 @@ Derivative works have been also created from these files for this
 project, that are located inside the `res` directory. A `LICENSE`
 file is also provided to describe the relationship between the
 original and derived works.
+
+## Copyright notice
+
+Microsoft®, Linux®, Sony® and PlayStation® are registered trademarks of
+their respective owners.