Clean up the README and wiki documentation

[aidangarske]

• Removes the not yet officially supported note and the Skoll and Fenrir badges from the README.
• Repoints the wiki and CI links from the fork to wolfSSL/wolfSPDM.
• Corrects the Supported Operations heading that labeled SPDM as an RFC to DSP0274 and DSP0277.
• Reframes the README top as one SPDM implementation with a shared core and two closely related modes, the standard DMTF requester
  and the TCG TPM binding, with standalone and wolfTPM build recipes.
• Removes the hardcoded context footprint sizes from the README and two wiki pages.
• Removes em dashes throughout the README and wiki pages.
• Documentation only, no code or build changes.