Cleanup. PDFs are now stored in the releases area of GitHub.

Signed-off-by: Stephano Cetola <scetola@linuxfoundation.org>

Some minor cleanup was needed to get the RISC-V spec template working. Also, this sets up automation for building a PDF using GitHub workflows.
Signed-off-by: Stephano Cetola <scetola@linuxfoundation.org>

Add a note to mention this spec has not proceeded with the ratification plan yet.

Changes to build PDF file

PDF is built under https://github.com/riscv/docs-templates

Restructure the document

- Convert markdown file to AsciiDoc
- Separate External reference sections to appendix.adoc
- Separate Contributing sections to contributor.adoc
- Add changelog.adoc

Update RISCV-SMBIOS.md

Correct typo "mvendroid" to "mvendorid"

Add more descriptions toExternal Reference

Update RISCV-SMBIOS.md

correct the additional info version

update version
fix the value of length(offset 2) in SMBIOS type 44
add reference link in Processor Architecture Types table.

update processor-specific block standard header

added some changes to the wording

Made by Jason

Update RISCV-SMBIOS.md