fix typos (#1042)

spec/core/ics-004-channel-and-packet-semantics/UPGRADES.md

@@ -38,7 +38,7 @@ enum ChannelState {
 
 - In `ChanUpgradeInit`, the initializing chain that is proposing the upgrade should store the channel upgrade.
 - The counterparty chain executing `ChanUpgradeTry` that accepts the upgrade should store the channel upgrade, set the channel state from `OPEN` to `FLUSHING`, and start the flushing timer by storing an upgrade timeout.
-- Once the initiating chain verifies the counterparty is in `FLUSHING`, it must also move to `FLUSHING` unless all in-flight packets are already flushed on both ends, in which case it must move directly to `FLUSHCOMPLETE`. The initator will also store the counterparty timeout to ensure it does not move to `FLUSHCOMPLETE` after the counterparty timeout has passed.
+- Once the initiating chain verifies the counterparty is in `FLUSHING`, it must also move to `FLUSHING` unless all in-flight packets are already flushed on both ends, in which case it must move directly to `FLUSHCOMPLETE`. The initiator will also store the counterparty timeout to ensure it does not move to `FLUSHCOMPLETE` after the counterparty timeout has passed.
 - The counterparty chain must prove that the initiator is  also in `FLUSHING` or completed flushing in `FLUSHCOMPLETE`. The counterparty will store the initiator timeout to ensure it does not move to `FLUSHCOMPLETE` after the initiator timeout has passed.
 
 `FLUSHING` is a "blocking" state in that they will prevent the upgrade handshake from proceeding until the in-flight packets on both channel ends are flushed. Once both sides have moved to `FLUSHCOMPLETE`, a relayer can prove this on both ends with `ChanUpgradeOpen` to open the channel on both sides with the new parameters.
@@ -354,7 +354,7 @@ function restoreChannel(
   channel = provableStore.get(channelPath(portIdentifier, channelIdentifier))
   errorReceipt = ErrorReceipt{
     channel.upgradeSequence,
-    "upgrade handshake is aborted", // constant string changable by implementation
+    "upgrade handshake is aborted", // constant string changeable by implementation
   }
   provableStore.set(channelUpgradeErrorPath(portIdentifier, channelIdentifier), errorReceipt)
   channel.state = OPEN
@@ -560,7 +560,7 @@ function chanUpgradeTry(
   if counterpartyUpgradeSequence < channel.upgradeSequence {     
     errorReceipt = ErrorReceipt{
       channel.upgradeSequence - 1,
-      "sequence out of sync", // constant string changable by implementation
+      "sequence out of sync", // constant string changeable by implementation
     }
     provableStore.set(channelUpgradeErrorPath(portIdentifier, channelIdentifier), errorReceipt)
     return