fix: functions:build example (#5618)

* Fix for functions:build example

I was creating a plugin and running the example command is not working as `timeout` and `name` does not exist for the functions:build command

* chore: update docs

---------

Co-authored-by: Karin Hendrikse <30577427+khendrikse@users.noreply.github.com>

Author: biruwon

docs/commands/functions.md

@@ -34,7 +34,7 @@ netlify functions
 
 ```bash
 netlify functions:create --name function-xyz
-netlify functions:build --name function-abc --timeout 30s
+netlify functions:build --functions build/to/directory --src source/directory
 ```
 
 ---

src/commands/functions/functions.mjs

@@ -39,7 +39,7 @@ The ${name} command will help you manage the functions in this site`,
     )
     .addExamples([
       'netlify functions:create --name function-xyz',
-      'netlify functions:build --name function-abc --timeout 30s',
+      'netlify functions:build --functions build/to/directory --src source/directory',
     ])
     .action(functions)
 }