Add RVI abbreviation to list of abbreviations. (#191)

Signed-off-by: Andrei Warkentin <andrei.warkentin@intel.com>

intro.adoc

@@ -60,6 +60,7 @@ Most terminology has the standard RISC-V meaning. This table captures other term
 | OSV             | Operating System Vendor.
 | OS              | Operating System or Hypervisor.
 | Profile         | RISC-V Profile cite:[Profile].
+| RVI             | RISC-V International.
 | SBI             | _RISC-V Supervisor Binary Interface Specification_ cite:[SBI].
 | SMBIOS          | _System Management BIOS (SMBIOS) Reference Specification_ cite:[SMBIOS].
 | SoC             | System on a chip, a combination of processor and supporting chipset logic in single package.