Clarify freeze/unfreeze commands' purpose in help text

Author: blokyk

README.md

@@ -112,8 +112,8 @@ Commands:
   remove        Removes one pin entry
   import-niv    Try to import entries from Niv
   import-flake  Try to import entries from flake.lock
-  freeze        Freeze a pin entry
-  unfreeze      Thaw a pin entry
+  freeze        Freezes a pin entry, preventing it from being changed during an update
+  unfreeze      Thaws a pin entry, allowing it to be changed during an update like a normal pin
   get-path      Evaluates the store path to a pin, fetching it if necessary. Don't forget to add a GC root
   help          Print this message or the help of the given subcommand(s)
 

src/main.rs

@@ -547,10 +547,10 @@ pub enum Command {
     /// Try to import entries from flake.lock
     ImportFlake(ImportFlakeOpts),
 
-    /// Freeze a pin entry
+    /// Freezes a pin entry, preventing it from being changed during an update
     Freeze(FreezeOpts),
 
-    /// Thaw a pin entry
+    /// Thaws a pin entry, allowing it to be changed during an update like a normal pin
     Unfreeze(FreezeOpts),
 
     /// Evaluates the store path to a pin, fetching it if necessary. Don't forget to add a GC root