#87 CIMC check clarifications around multi-step upgrades and RNE differences

[monrog2]

Script changes

1. Update check to flag is CIMC is an old version and may need multi-step CIM Cupgrade
2. Update link to mkdoc
3. Update action to vet RNE

Doc changes

1. Removed link to APIC matrix, as it looks like it no longer calls out CIMC
2. clarified why RNE should be vetted, regardless of check
3. Added link to UCS CIMC matrix

[monrog2]

Local pytest output

[Check  1/1] APIC CIMC Compatibility...                                                                          FAIL - UPGRADE FAILURE!!
  Node ID  Model           Current CIMC version  Catalog Recommended CIMC Version  Warning
  -------  -----           --------------------  --------------------------------  -------
  node-1   APIC-SERVER-L2  1.5(4e)               4.0(2f)                           Multi-step Upgrade may be required, check UCS CIMC Matrix.
  node-2   APIC-SERVER-L2  1.5(4e)               4.0(2f)                           Multi-step Upgrade may be required, check UCS CIMC Matrix.
  node-3   APIC-SERVER-M1  1.5(4e)               3.0(4j)                           Multi-step Upgrade may be required, check UCS CIMC Matrix.

  Recommended Action: Check Release note of APIC Model/version for latest recommendations.
  Reference Document: https://datacenter.github.io/ACI-Pre-Upgrade-Validation-Script/validations/#compatibility-cimc-version


[Check  1/1] APIC CIMC Compatibility...                                                                          FAIL - UPGRADE FAILURE!!
  Node ID  Model           Current CIMC version  Catalog Recommended CIMC Version  Warning
  -------  -----           --------------------  --------------------------------  -------
  node-1   APIC-SERVER-L2  3.0(4l)               4.0(2f)
  node-2   APIC-SERVER-L2  3.0(4l)               4.0(2f)

  Recommended Action: Check Release note of APIC Model/version for latest recommendations.
  Reference Document: https://datacenter.github.io/ACI-Pre-Upgrade-Validation-Script/validations/#compatibility-cimc-version


[Check  1/1] APIC CIMC Compatibility...                                                                                              PASS