Possibly outdated documentation about type `ProtVer`

In `Ledger.Conway.PParams`, there is a code snippet (shown in the PDFs):
```agda
ProtVer : Type
ProtVer = ℕ × ℕ

instance
Show-ProtVer : Show ProtVer
Show-ProtVer = Show-×

data pvCanFollow : ProtVer → ProtVer → Type where
canFollowMajor : pvCanFollow (m , n) (m + 1 , 0)
canFollowMinor : pvCanFollow (m , n) (m , n + 1)
```
Way below there is a (commented out) comment:
```agda
% Retiring ProtVer's documentation since ProtVer is retired.
% \ProtVer{} represents the protocol version used in the Cardano ledger.
% It is a pair of natural numbers, representing the major and minor version,
% respectively.
```