Update Sphincs+ Markdown documentation from YAML

[SWilson4]

I used "[skip ci]" a little too liberally on #1683 and missed the fact that Markdown documentation needed to be updated to reflect YAML changes. This PR does that.

• Does this PR change the input/output behaviour of a cryptographic algorithm (i.e., does it change known answer test values)? (If so, a version bump will be required from x.y.z to x.(y+1).0.)
• Does this PR change the list of algorithms available -- either adding, removing, or renaming? Does this PR otherwise change an API? (If so, PRs in fully supported downstream projects dependent on these, i.e., oqs-provider and OQS-OpenSSH will also need to be ready for review and merge by the time this is merged.)

[praveksharma]

LGTM!