Reformat LICENSE.txt so GitHub sees it as zlib.

LICENSE.txt

@@ -1,23 +1,17 @@
-
-   Copyright (c) 2001-2020 Ryan C. Gordon and others.
-
-   This software is provided 'as-is', without any express or implied warranty.
-   In no event will the authors be held liable for any damages arising from
-   the use of this software.
-
-   Permission is granted to anyone to use this software for any purpose,
-   including commercial applications, and to alter it and redistribute it
-   freely, subject to the following restrictions:
-
-   1. The origin of this software must not be misrepresented; you must not
-   claim that you wrote the original software. If you use this software in a
-   product, an acknowledgment in the product documentation would be
-   appreciated but is not required.
-
-   2. Altered source versions must be plainly marked as such, and must not be
+Copyright (c) 2001-2021 Ryan C. Gordon <icculus@icculus.org> and others.
+  
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+  
+1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required. 
+2. Altered source versions must be plainly marked as such, and must not be
    misrepresented as being the original software.
-
-   3. This notice may not be removed or altered from any source distribution.
-
-       Ryan C. Gordon <icculus@icculus.org>
-
+3. This notice may not be removed or altered from any source distribution.