Avoid non-ASCII characters when not necessary

LICENSE

@@ -1,6 +1,6 @@
 The MIT License
 
-Copyright (c) 1997-2024, Carsten Sørensen and RGBDS contributors.
+Copyright (c) 1996-2025, Carsten Sørensen and RGBDS contributors.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to

README.md

@@ -6,7 +6,7 @@ for the Game Boy and Game Boy Color. It consists of:
 - RGBASM (assembler)
 - RGBLINK (linker)
 - RGBFIX (checksum/header fixer)
-- RGBGFX (PNG‐to‐Game Boy graphics converter)
+- RGBGFX (PNG-to-Game Boy graphics converter)
 
 This is a fork of the original RGBDS which aims to make the programs more like
 other UNIX tools.
@@ -143,7 +143,7 @@ The RGBDS source code file structure is as follows:
 - 2010-09-25: Sørensen continues development of
   [ASMotor](https://github.com/asmotor/asmotor) to this day.
 - 2015-01-18: stag019 begins implementing [RGBGFX](https://github.com/stag019/rgbgfx),
-  a PNG‐to‐Game Boy graphics converter, for eventual integration into RGBDS.
+  a PNG-to-Game Boy graphics converter, for eventual integration into RGBDS.
 - 2016-09-05: RGBGFX is
   [integrated](https://github.com/gbdev/rgbds/commit/c3c31138ddbd8680d4e67957e387f2816798a71b)
   into Bentley's repository.

man/rgbds.7

@@ -57,7 +57,7 @@ to this day.
 .It
 2015-01-18:
 .An stag019
-begins implementing RGBGFX, a PNG‐to‐Game Boy graphics converter, for eventual integration into RGBDS.
+begins implementing RGBGFX, a PNG-to-Game Boy graphics converter, for eventual integration into RGBDS.
 .It
 2016-09-05: RGBGFX is integrated into Bentley's repository.
 .It

src/gfx/pal_packing.cpp

@@ -169,7 +169,7 @@ private:
 	// This function should stay private because it returns a reference to a unique object
 	std::unordered_set<uint16_t> &uniqueColors() const {
 		// We check for *distinct* colors by stuffing them into a `set`; this should be
-		// faster than "back-checking" on every element (O(n²))
+		// faster than "back-checking" on every element (O(n^2))
 		static std::unordered_set<uint16_t> colors;
 
 		colors.clear();