Small update for upgrades.md (#1876)

Updates for recent switch to `Versions` and small clarifications. 


---------

Co-authored-by: tbro <[email protected]>
Co-authored-by: Abdul Basit <[email protected]>

Author: tbro

doc/upgrades.md

@@ -1,7 +1,7 @@
 # Upgrades
 
 Hotshot protocol supports upgrades through an Upgrade proposal mechanism. The Upgrade proposal is broadcast separately
-from the `QuorumProposal`, typically several views in advance of its attachment. The goal is to ensure ample time for
+from the `QuorumProposal`, typically several views before the upgrade is attempted. The goal is to ensure ample time for
 nodes to receive and prepare for the upgrade process.
 
 After enough votes have been collected on the `UpgradeProposal`, an `UpgradeCertificate` is formed. This is attached to
@@ -33,10 +33,10 @@ hash:
   different proposals of the same version upgrade, ensuring nodes vote and execute the correct one. It consists of a
   sequence of 32 bytes.
 
-These are defined in [NodeType implementation](../types/src/v0/mod.rs) for the Types (`SeqTypes` in our case).
+These are defined in [Versions implementation](../types/src/v0/mod.rs) for the Type (`SequencerVersions` in our case).
 
 ```rust
-impl NodeType for SeqTypes {
+impl Versions for SequencerVersions {
 	type Base = StaticVersion<0, 1>;
 	type Upgrade = StaticVersion<0, 2>;
 	const UPGRADE_HASH: [u8; 32] = [
@@ -53,7 +53,7 @@ parameters use Unix timestamps for the same purpose.
 
 To simplify configuration, these parameters are fetched from the genesis TOML file and set in the Hotshot config. The
 TOML file can include either view-based parameters or time-based parameters, but not both. Furthermore, the start and
-stop voting parameters for both time-based and view-based upgrades are optional. Start parameter is set 0 so that voting
+stop voting parameters for both time-based and view-based upgrades are optional. If omitted, start parameter will be set to 0 so that voting
 begins as soon as node is started while the stop parameter is set to a maximum value so that the nodes keep voting until
 enough votes are collected.