fix: edit messages for "sf alias set"

messages/alias.set.md

@@ -1,30 +1,36 @@
 # summary
 
-Set one or more aliases.
+Set one or more aliases on your local computer.
 
 # description
 
-You can associate an alias with only one value at a time. If you’ve set an alias multiple times, the alias points to the most recent value.
+Aliases are user-defined short names that make it easier to use the CLI. For example, users often set an alias for a scratch org usernames because they're long and unintuitive.  Check the --help of a CLI command to determine where you can use an alias.
 
-# examples
+You can associate an alias with only one value at a time. If you set an alias multiple times, the alias points to the most recent value. Aliases are global; after you set an alias, you can use it in any Salesforce DX project on your computer.
+
+Use quotes to specify an alias value that contains spaces. You typically use an equal sign to set your alias, although you don't need it if you're setting a single alias in a command.
 
-- <%= config.bin %> <%= command.id %>
+# examples
 
 - Set an alias for a scratch org username:
-  <%= config.bin %> <%= command.id %> my-alias=[email protected]
+
+  <%= config.bin %> <%= command.id %> my-scratch-org=[email protected]
 
 - Set multiple aliases with a single command:
-  <%= config.bin %> <%= command.id %> my-alias=[email protected] my-other-alias=[email protected]
+
+  <%= config.bin %> <%= command.id %> my-scratch-org=[email protected] my-other-scratch-org=[email protected]
 
 - Set an alias that contains spaces:
+
   <%= config.bin %> <%= command.id %> my-alias='alias with spaces'
 
-- Single aliases can be set without an equal sign
-  <%= config.bin %> <%= command.id %> my-alias [email protected]
+- Set a single alias without using an equal sign:
+
+  <%= config.bin %> <%= command.id %> my-scratch-org [email protected]
 
 # error.ArgumentsRequired
 
-You must provide one or more aliases to set. Use the --help flag to see more examples.
+You must provide one or more aliases to set. Use the --help flag to see examples.
 
 # error.ValueRequired