drop non-Linux support

openadk.org/content/_index.md

@@ -25,8 +25,7 @@ ARM, AVR32, Blackfin, C6X, CR16, CRIS, C-Sky, Epiphany, FR-V, FT32, H8/300,
 HPPA, IA64, KVX, LM32, Loongarch, M32C, M32R, M68K, METAG, Microblaze, MIPS, MIPS64, MN10300,
 Moxie, MSP430, NDS32, NIOS2, OR1K, PPC, PPC64, RISCV32, RISCV64, RX, S/390, SH,
 SPARC, SPARC64, Tile, V850, X86, X86_64 and Xtensa. You can use it on any
-computer running Linux, BSD, MacOS X or Windows (Cygwin) to create the
-toolchains.
+computer running Linux to create the toolchains.
 
 # Embedded Systems and more