Add ``supported Sound devices'' section, with the following cards
listed as supported (by pcm), which reflects the current pcm(4) and related
manpages situation and NOTES comments.

• Advance Asound 100, 110 and Logic ALS120
• Aureal Vortex1/Vortex2 and Vortex Advantage based soundcards by a third party driver (URL given, Submitted by Bill Huey <billh@gnuppy.monkey.org> and sobomax on IRC)
• Creative Labs SB16, SB32, SB AWE64 (including Gold), Vibra16, SB PCI, SB Live! and most compatible cards
• Crystal Semiconductor CS461x/462x Audio Accelerator
• Crystal Semiconductor CS428x Audio Controller
• CS4237, CS4236, CS4232, CS4231 (ISA)
• ENSONIQ AudioPCI ES1370/1371
• ESS ES1868, ES1869, ES1879, ES1888
• Gravis UltraSound PnP, MAX
• NeoMagic 256AV/ZX (PCI)
• OPTi931 (ISA)
• Trident 4DWave DX/NX (PCI)
• Yahama OPL-SAx (ISA)